Mindfulness-based Interventions Across the Cancer Continuum in the United States: A Scoping Review

Abstract

Objective

To review mindfulness-based interventions (MBIs) tested in randomized controlled trials (RCT) across the cancer continuum.

Data Source

Articles identified in PubMed, CINAHL, Web of Science, PsycINFO, and Embase.

Study Inclusion and Exclusion Criteria

Two independent reviewers screened articles for: (1) topic relevance; (2) RCT study design; (3) mindfulness activity; (4) text availability; (5) country (United States); and (6) mindfulness as the primary intervention component.

Data Extraction

Twenty-eight RCTs met the inclusion criteria. Data was extracted on the following variables: publication year, population, study arms, cancer site, stage of cancer continuum, participant demographic characteristics, mindfulness definition, mindfulness measures, mindfulness delivery, and behavioral theory.

Data Synthesis

We used descriptive statistics and preliminary content analysis to characterize the data and identify emerging themes.

Results

A definition of mindfulness was reported in 46% of studies and 43% measured mindfulness. Almost all MBIs were tested in survivorship (50%) or treatment (46%) stages of the cancer continuum. Breast cancer was the focus of 73% of cancer-site specific studies, and most participants were non-Hispanic white females.

Conclusion

The scoping review identified 5 themes: (1) inconsistency in defining mindfulness; (2) differences in measuring mindfulness; (3) underrepresentation of racial/ethnic minorities; (4) underrepresentation of males and cancer sites other than breast; and (5) the lack of behavioral theory in the design, implementation, and evaluation of the MBI.

Keywords

mindfulness mindfulness-based interventions cancer continuum scoping review randomized controlled trials

Objective

The American Cancer Society (ACS) estimates 1 958 310 new cases of cancer will be diagnosed, and 609 820 deaths from cancer will occur in the United States in 2023.¹ The cancer continuum is a useful framework to identify gaps in knowledge and research evidence, and to recognize areas for improvement in care across various cancer stages.² The stages included in the cancer continuum are: etiology (i.e., origin of cancer), prevention (i.e., actions to lower risk of cancer), detection (i.e., screening for cancer), diagnosis (i.e., confirming the presence of cancer and shared decision making with healthcare professionals), treatment (i.e., curative and/or non-curative healthcare related to a cancer diagnosis), survivorship (i.e., health promotion after a cancer diagnosis), and end of life (i.e., comfort during end of life).²

An application of the cancer continuum is using it as a framework to guide reviews of cancer-related topics included in the scientific literature. However, reviews using the cancer continuum as a guide are challenged with providing clear definitions of each stage.³ For example, health-related behaviors often overlap between the stages of the cancer continuum (e.g., colonoscopy as prevention and detection).² Furthermore, including specific stages (e.g., etiology, end of life) in reviews may result in too many sources that are not relevant to the health topic being explored and, as a consequence, may limit meaningful comparisons depending on the health topic. An example of including too many sources that are irrelevant is that perceived stress and anxiety have been identified as significant barriers across all stages of the continuum including etiology (suppressed immune system), prevention (unhealthy behaviors), detection/diagnosis (no-shows or cancelled appointments), treatment (low adherence to treatments and symptom management), survivorship (fear of cancer reoccurrence), and end of life (lower perceived quality of life).^4-9

Therefore, Mindfulness-Based Interventions (MBIs) aimed to reduce stress and anxiety have the potential to improve health outcomes among individuals in different stages across the cancer continuum.¹⁰ A systematic review and meta-analysis of randomized controlled trials (RCTs) support the use of MBIs to reduce psychological distress, anxiety, depression, fear of cancer recurrence, fatigue, sleep disturbances, and pain within the treatment and survivorship stages of the cancer continuum.¹¹ However, there is a gap of research evidence of the usefulness of MBIs to reduce anxiety among individuals in other stages in the cancer continuum. In addition, since the popularity and use of MBIs has evolved over time, a current scoping review is warranted to determine how they are being implemented across the cancer continuum.

The purpose of scoping reviews is to provide a preliminary assessment of the potential size and scope of the available research and identify gaps in the evidence for a specific topic. The goal of the current scoping review is to assess MBIs tested in RCTs across specific stages of the cancer continuum to determine the scope of the evidence, identify any research gaps, and to summarize findings. We restrict MBIs tested in RCTs in this scoping review to limit potential biases that may be included in other study designs when testing interventions.

Methods

This study used the advanced scoping review methodology proposed by Levac et al,¹² that includes 6 stages aimed to clarify and enhance Arksey and O’Malley’s original methodological framework for conducting scoping reviews.¹³ The stages are as follows: (1) clarifying and linking purpose and research question; (2) balancing feasibility with breadth and comprehensiveness of the scoping process; (3) using an iterative team approach to selecting studies; (4) extracting data; (5) incorporating a numerical summary and qualitative thematic analysis, reporting results, and considering the implications of study findings to policy, practice, or research; and (6) incorporating consultation with stakeholders as a required knowledge translation component of scoping study methodology.¹² This study also used the Preferred Reporting Items for Systematic Reviews – Scoping Reviews (PRISMA-ScR) checklist to guide the reporting of results.¹⁴

Data Sources

Cancer and mindfulness research fields are interdisciplinary (e.g., medicine, nursing, psychology, public health), thus, the research team utilized PubMed, CINAHL, Web of Science, PsycINFO, and Embase databases to provide a comprehensive assessment of the use of MBIs across the cancer continuum. All databases were searched individually to account for variations in search syntax and Medical Subject Headings (MeSH) terminology. The lead author (BE) met with members of the research team and created a comprehensive MeSH keyword list pertaining to mindfulness (i.e., mindfulness, meditation, mindfulness-based stress reduction, mind-body relations, metaphysical, mentalization, consciousness, stress, cognitive behavioral therapy, acceptance and commitment therapy) and cancer (i.e., cancer, prevention, screening, treatment, diagnostic techniques and procedures, general surgery, preoperative period, preoperative care, surgical procedure-operative, survivorship, early detection of cancer, cancer screening, resilience, postoperative period, and postoperative care).

A potential search strategy was assessed using every combination of the mindfulness and cancer keyword list in PubMed. The search resulted in 14 175 articles and based on the methodological framework for conducting scoping reviews,¹² the research team revised the original search strategy and the MeSH terms “consciousness” and “stress” were removed from the mindfulness list and the cancer continuum keyword list was limited to the single keyword “cancer.”

The search strategy was repeated using the revised key word list. The revised search resulted in 5431 articles and was determined to be within the capacity of the research team. As time passed during the process, we updated the search and reviewed an additional 8075 articles prior to submission of the manuscript for publication. We used the following MeSH terms for our literature search: “mindfulness” or “meditation” or “mindfulness-based stress reduction” or “mind-body relations, metaphysical” or “mentalization” or “cognitive behavioral therapy” or “acceptance and commitment therapy” and “cancer.”

Two filters were used during the search process. One filter for language (English) was used for comprehension, and a filter for publications dated 2000 to mid-2022 was applied to provide the relevant assessment of the contemporary scientific literature.

Inclusion and Exclusion Criteria

Article selection was conducted by 2 independent reviewers (BE and MR) using Covidence software-a web-based systematic review management tool designed to facilitate the process of conducting literature reviews.¹⁵ Reviewers cast a single vote to either include or exclude each article, and any conflicting decisions were passed to the next stage of screening for further review. An agreement percentage between the 2 reviewers was calculated using the following formula: (total articles reviewed - number of conflicting decisions)/total articles reviewed.

The inclusion criteria for the search were: (1) topic relevance: the article must include a mindfulness MeSH keyword (i.e., mindfulness, meditation, mindfulness-based stress reduction, mind-body relations, metaphysical, mentalization, cognitive behavioral therapy, or acceptance and commitment therapy) and cancer within the title or abstract, and the purpose of the article must be within the context of cancer prevention, detection, diagnosis, treatment, or survivorship; (2) study design: the article must utilize a RCT study design characterized by a randomization of participants to independent study conditions; (3) mindfulness activity: the article must include a mindfulness activity in the intervention; (4) text availability: the full text of the article must be available for review; (5) country: the article must be conducted in the United States due to cultural differences in the perception of mindfulness; and (6) mindfulness as the primary intervention component: the article must incorporate mindfulness as the primary component (i.e., previous evidence-based MBIs, interventions which utilize mindfulness as the theoretical foundation, or interventions with mindfulness as the primary intervention activity).

The PRISMA-ScR flow diagram (Figure 1) shows the search and selection process. A total of 13 506 articles were identified, and 3975 duplicates were removed. Of the 9531 remaining articles, 8484 articles were excluded during the title and abstract screening phase based on topic irrelevance (5479) and non-RCT study design (3005). The remaining 1047 articles were assessed using full text review. A total of 1019 articles were excluded for the following reasons: 585 lacked mindfulness as an intervention activity; 200 were not conducted in the United States; 101 full texts were unavailable; 81 for other reasons including the publication was an abstract, protocol, thesis, or dissertation; and 52 did not include mindfulness as the primary component. During data cleaning, the lead author (BE) corrected misclassified articles, whenever applicable. The total agreement percentage was 92%, and a final sample of 28 studies were included in this scoping review.^16-43

Figure 1.

PRISMA-ScR flow diagram of search and selection process.

Data Extraction

The lead author developed a data extraction table using Microsoft Excel to capture relevant findings from the included studies and proposed potential variables of interest to the research team. Variables were discussed, revised, and finalized before beginning data extraction. Two members of the study team (BE and MR) completed data extraction from the 28 studies. Table 1 lists the following extracted variables: first author, year of publication, population including the number of participants, study arms, cancer site, stage of cancer continuum, participant demographic characteristics (i.e., age, gender, race, ethnicity), mindfulness definition, mindfulness measures, mindfulness delivery, and the use of behavioral theory to guide the development, implementation, or evaluation of the intervention.

Table 1.

Summary of RCTs (n = 28) Assessing Mindfulness-based Interventions Across the Cancer Continuum in the United States (1/1/2000-5/10/2022).

First Author (Year of Publication)	Population (Number of Participants)	Study Arms	Cancer Site	Stage of Cancer Continuum	Participant Demographic Characteristics^a	Mindfulness Definition	Mindfulness Measure	Mindfulness Delivery	Behavioral Theory
Black (2017)	CRC patients receiving an adjuvant chemotherapy session (N = 57)	1. Mindfulness 2. Resting exposure 3. Attention control	Colorectal	Treatment	Age (mean): 54.0	“The awareness that emerges through paying attention on purpose, in the present moment, and nonjudgmentally to the unfolding of experience moment by moment”	MAAS	Recorded audio and video modules via mobile tablet	NR
					Gender: 51% Male
					Race: NR
					Ethnicity: 67% Non-Hispanic
Blaes (2016)	Cancer survivors within 6 months of completion of chemotherapy or radiation (N = 42)	1. Mindfulness-based cancer recovery 2. Wait-list control	69% Breast 31% Other	Survivorship	Age (mean of study arms): 55.0; 57.0	NR	NR	In-person	NR
					Gender: 90% Female
					Race: NR
					Ethnicity: NR
Bower (2015)	Females with early-stage breast cancer before age 50 who completed cancer treatment (N = 71)	1. Mindful awareness practices 2. Wait-list control	Breast	Survivorship	Age (mean of study arms): 46.1; 47.7	NR	NR	In-person	NR
					Gender: 100% Female
					Race: 76% White
					Ethnicity: NR
Bower (2021)	Females with breast cancer at or before age 50 who completed treatment and had elevated depressive symptoms (N = 247)	1. Mindful awareness practices 2. Survivorship education 3. Wait-list control	Breast	Survivorship	Age (mean): 45.4	“Bringing attention to one’s present moment experiences, including thoughts, feelings, and physical sensations, with openness, curiosity, and acceptance”	NR	In-person	NR
					Gender: 100% Female
					Race: 82% White
					Ethnicity: 90% Non-Hispanic
Clark (2012)	Patients with chemotherapy-induced peripheral neuropathy (N = 26)	1. Yoga 2. Reiki 3. Mindfulness meditation 4. Education control	65% Breast 35% Other	Treatment	Age (mean): 59.0	NR	MAAS	In-person	NR
					Gender: 88% Female
					Race: 81% White
					Ethnicity: NR
Crane-Okada (2012)	Female breast cancer survivors age 50+ at 12 months or more following treatment (N = 49)	1. Mindful Movement program 2. Control	Breast	Survivorship	Age (mean of study arms): 64.8; 66.1	“Moment-to-moment, present-centered, purposive nonjudgmental awareness”	MAAS; SCS; FFMQ; EQ	In-person	NR
					Gender: 100% Female
					Race: NR
					Ethnicity: 79% Non-Hispanic White
Henderson (2012)	Females with early-stage breast cancer (N = 180)	1. MBSR 2. Nutrition education program 3. Usual supportive care	Breast	Treatment	Age (mean): 49.8	“The practice of purposefully non-judgmentally paying attention in the present moment”	NR	In-person	SCT
					Gender: 100% Female
					Race: 95% White
					Ethnicity: NR
Hunter (2020)	Patients undergoing chemotherapy for solid tumors (N = 474)	1. Mindfulness 2. Relaxing music 3. Standard care	85% Breast 15% Other	Treatment	Age (%): 68% < 60	NR	NR	In-person and recorded audio for home practice	NR
					Gender: 92% Female
					Race/ethnicity: 86% Non-Hispanic White
Johns (2016)	Persistently fatigued breast and CRC survivors (N = 71)	1. MBSR 2. Psychoeducation and support	85% Breast 15% colorectal	Survivorship	Age (mean of study arms): 56.4; 56.9	“A non-judging mental state whereby one attends to and purposefully manages one’s awareness of what is happening in the present moment”	Mindfulness practice	In-person and recorded audio for home practice	NR
					Gender: 90% Female
					Race: 70% White
					Ethnicity: NR
Johns (2015)	Persistently fatigued cancer survivors (N = 35)	1. MBSR 2. Wait-list control	86% Breast 14% Other	Survivorship	Age (mean of study arms): 55.7; 58.8	“Intentionally directing attention to one’s present moment experience without judging that experience as positive or negative”	FFMQ; Mindfulness practice	In-person and recorded audio for home practice	NR
					Gender: 94% Female
					Race: 80% White
					Ethnicity: NR
Kubo (2019)	Cancer patients, currently receiving or had received treatment within the prior 6 months (N = 97) and their caregivers	1. Headspace mindfulness intervention 2. Wait-list control	29% Breast 22% Hematologic 49% Other	Treatment	Age (mean of study arms): 56.7; 59.3	“A psychological process of bringing one’s attention to the present moment with an attitude of nonjudgment, Acceptance, and openness”	FFMQ; Mindfulness practice	Commercially available mindfulness app	NR
					Gender: 68% Female
					Race: 65% White
					Ethnicity: NR
Lehto (2015)	Patients receiving treatment for advanced lung cancer (N = 40)	1. Mindfulness-based therapy 2. Attention control	Lung	Treatment	Age (mean): 66.2	NR	NR	In-person in the home environment	NR
					Gender: 68% Female
					Race: 85% White
					Ethnicity: 90% Non-Hispanic/Latino
Lengacher (2009)	Female breast cancer survivors (N = 84)	1. MBSR 2. Usual care	Breast	Survivorship	Age (mean): 57.5	NR	Mindfulness practice	In-person and recorded audio for home practice	NR
					Gender: 100% Female
					Race/ethnicity: 73% Non-Hispanic White
Lerman (2012)	Female cancer survivors (N = 68)	1. MBSR derived cancer recovery and wellness intervention 2. Wait-list control	71% Breast 29% Other	Survivorship	Age^b (mean of study arms): 56.4; 57.5	“Moment-to-moment awareness while remaining nonjudgmental and accepting of different sensations, thoughts, and perceptions as they occur”	Mindfulness practice	In-person	NR
					Gender: 100% Female
					Race/ethnicity^b: 85% White
Messer (2019)	Cancer survivors (N = 21)	1. MBSR derived online mindfulness training 2. Usual care control	NR	Survivorship	Age (mean): 51.0	NR	NR	Online recorded audio	NR
					Gender: 76% Female
					Race: 80% White
					Ethnicity: NR
Milbury (2021)	Females with lung cancer undergoing treatment (N = 54)	1. Mindfulness training 2. Psychoeducation	Lung	Treatment	Age (mean): 65.7	NR	NR	Commercially available video conferencing software	NR
					Gender: 100% Female
					Race/ethnicity: 69% Non-Hispanic White
Millstine (2019)	Females with a recent diagnosis of breast cancer and planned to undergo surgical treatment (N = 51)	1. Muse mindfulness meditation 2. Stress-reduction control	Breast	Treatment	Age^b (mean of study arms): 55.8; 55.9	NR	NR	Commercially available meditation app and feedback headband	NR
					Gender^b: 100% Female
					Race/ethnicity^b: 96% Non-Hispanic White
Monti (2006)	Females with cancer (N = 111)	1. MBSR derived Mindfulness-Based art therapy 2. Wait-list control	46% Breast 17% GYN 37% Other	Treatment	Age (mean): 53.6	NR	NR	In-person and recorded audio for home practice	SRT
					Gender: 100% Female
					Race: 75% Caucasian
					Ethnicity: N/A
Monti (2013)	Breast cancer patients with high stress (N = 251)	1. MBSR derived Mindfulness-Based art therapy 2. Breast cancer support 3. Untreated control	Breast	Treatment	Age (mean of study arms): 56.4; 56.9; 57.4	NR	NR	In-person with workbook for home practice	NR
					Gender: 100% Female
					Race: 54% White 32% Black
					Ethnicity: NR
Nakamura (2013)	Cancer survivors with clinically significant self-reported sleep disturbance (N = 57)	1. Mind-body bridging 2. Mindfulness meditation 3. Sleep hygiene education	54% Breast 46% Other	Survivorship	Age (mean of study arms): 50.8; 51.6; 55.4	“Paying attention in a particular way, on purpose, in the present moment, and nonjudgmentally”	FFMQ	In-person and CDs for home practice	NR
					Gender: 75% Female
					Race/ethnicity: 95% Non-Hispanic White
Price-Blackshear (2020)	Young breast cancer survivors (N = 118) and their partners	1. Couples Mindfulness-Based intervention 2. Individual Mindfulness-Based intervention	Breast	Survivorship	Age^b (mean of study arms): 38.8; 39.7	NR	MAAS; IMS	Online recorded videos, audio recordings, study manual	NR
					Gender: 100% Female
					Race^b: 84% White
					Ethnicity: NR
Rabin (2016)	Young adult cancer survivors (N = 35)	1. Relaxation (mindfulness) and exercise for wellness intervention 2. Wait-list control	NR	Survivorship	Age (mean): 33.6	NR	NR	In-person, CDs for home practice, coaching by phone, online forum	SCT; TTM
					Gender: 83% Female
					Race: 74% White
					Ethnicity: 86% Non-Hispanic
Ratcliff (2019)	Females undergoing stereotactic breast biopsy (N = 84)	1. Mindfulness-Based meditation 2. Focused breathing 3. Standard care	Breast	Diagnosis	Age^b (mean of study arms): 55.1; 55.1; 55.9	NR	NR	Recorded audio with in-person supervision	NR
					Gender^b: 100% Female
					Race^b: 74% White
					Ethnicity^b: 81% Non-Hispanic
Rosen (2018)	Females diagnosed with breast cancer within 5-years (N = 112)	1. App-delivered mindfulness training 2. Wait-list control	Breast	Treatment	Age (mean of study arms): 51.4; 53.2	“Intentional and non‐judgmental openness to and awareness of current thoughts, emotions, and sensations”	MAAS	Commercially available mindfulness app	NR
					Gender: 100% Female
					Race: 88% White
					Ethnicity: 93% Non-Hispanic
Thomas (2019)	Overweight and obese female cancer survivors (N = 51)	1. Mindfulness-Oriented recovery enhancement and exercise and nutrition counseling 2. Exercise and nutrition counseling	88% Breast 12% Other	Survivorship	Age (mean): 57.9	NR	MAIA	In-person	NR
					Gender: 100% Female
					Race: 96% White
					Ethnicity: 98% Non-Hispanic
Victorson (2017)	Males with prostate cancer (N = 43)	1. MBSR 2. Attention control	Prostate	Treatment	Age (mean of study arms): 69.0; 71.2	“A bivariate ‘mode’ or state of consciousness, involving: (a) The self-regulation of sustained attention and attentional shifting, which subsequently fosters the inhibition of secondary elaborative cognitive processing, and (b) an orientation of experience characterized by openness, curiosity and acceptance”	MAAS	In-person	NR
					Gender: 100% Male
					Race: 95% White
					Ethnicity: NR
Wirth (2019)	Cancer survivors (N = 36)	1. Mindfulness-Based cancer survivorship 2. Breathing control	53% Breast 20% prostate 27% Other	Survivorship	Age (mean): 63.9	“Paying attention in a particular way: on purpose, in the present moment, and nonjudgmentally”	MAAS	In-person	NR
					Gender: 72% Female
					Race/ethnicity: 83% European American
Witek Janusek (2019)	Females with newly diagnosed with breast cancer (N = 192)	1. MBSR 2. Control	Breast	Treatment	Age^b (mean of study arms): 55.0; 55.2	“Paying attention in a particular way: on purpose, in the present moment, and nonjudgmentally”	FFMQ; Mindfulness practice	In-person	NR
					Gender: 100% Female
					Race^b: 77% Caucasian
					Ethnicity^b: NR

Abbreviations: NR (not reported); RCTs (randomized controlled trials; CRC (colorectal cancer); GYN (gynecologic); MAAS (mindful attention awareness scale); FFMQ (5 facet mindfulness questionnaire); IMS (interpersonal mindfulness scale); MAIA (multidimensional assessment of interoceptive awareness); SCS (self-compassion scale); EQ (experiences questionnaire); MBSR (mindfulness-based stress reduction); SCT (social cognitive theory); SRT (self-regulation theory); and TTM (transtheoretical model).

^aDemographic characteristics: Age: years; Gender (%); Race (%); and Ethnicity (%).

^bAuthor reported missing data.

For the stages of the cancer continuum, we used a narrow definition of cancer prevention to only include MBIs with a specified purpose to prevent cancer. The other stages in the cancer continuum were not revised. Additionally, mindfulness definitions were included if the study explicitly defined mindfulness (e.g., “mindfulness is defined as…”), however, descriptions of the effects of mindfulness were not included as definitions (e.g., “mindfulness is designed to…”).

Data Synthesis

The lead author used descriptive statistics and preliminary content analysis to characterize the data. The data and emerging themes were presented to additional members of the research team who provided feedback and discussed thematic gaps that may be missing from the lead author’s initial interpretation of the results. The lead author obtained feedback from colleagues by making an oral presentation focused on the results of the review during a scientific research seminar. The results of the study were also discussed with a gastroenterologist (SC), who is a member of the research team, and is interested in the potential application of MBIs to reduce pre-procedural anxiety.

Results

The final sample included 28 studies with an agreement percentage of 92% for the 2 reviewers. In alignment with the inclusion criteria, all studies utilized a RCT study design and were conducted in the United States. The number of participants randomized in each study ranged from 21³⁰ to 474.²³ The majority (54%) of the studies identified the intervention as mindfulness-based or a derivative of a previously established MBI^{17,22,24,25,27-30,33,34,36,38,41-43} and 46% of studies incorporated mindfulness as the theoretical foundation and/or primary component of the intervention.^{16,18-21,23,26,31,32,35,37,39,40} The results are presented below: year of publication, stage of cancer continuum, cancer site, participant demographic characteristics, mindfulness definition, mindfulness measures, mindfulness delivery, use of behavioral theory, and emerging themes.

Year of Publication

Most studies (93%) were published after 2011^{16-27,29-33,35-43} with 25% of the studies being published in 2019.^{26,30,32,38,40,42,43}

Stage of Cancer Continuum

Most studies were conducted in the survivorship (50%)^{17-19,21,24,25,28-30,35-37,40,42} or treatment (46%)^{16,20,22,23,26,27,31-34,39,41,43} stages of the cancer continuum. Only one study (4%) of women undergoing stereotactic breast biopsy was conducted in the cancer diagnosis stage.³⁸ None of the studies used MBIs in the prevention and detection stages of the cancer continuum.

Cancer Site

The studies were categorized by cancer-specific site or by a mix of multiple cancer sites. Fifteen studies focused on cancer-specific sites (54%) including 11 breast,^{18,19,21,22,28,32,33,36,38,39,43} 2 lung,^27,31 1 colorectal,¹⁶ and 1 prostate cancer study.⁴¹ Of the 11 mixed cancer studies (39%), breast cancer comprised the majority of participants in all studies.^{17,20,23-26,29,34,35,40,42} Two studies did not report the patients’ cancer site.^30,37

Participant Demographic Characteristics

The central tendency metric reported for participant age varied across studies and were within the following ranges (years): 30-39 (7%),^36,37 40-49 (11%),^18,19,22 50-59 (61%),^{16,17,20,24-26,28-30,32-35,38-40,43} and 60+ (18%).^{21,27,31,41,42} One study did not report a central tendency metric for participants’ age.²³

The studies were categorized as gender-specific or non-gender specific based on the specific cancers. The majority of studies were gender-specific (57%),^{18,19,21,22,28,29,31-34,36,38-41,43} and of the gender-specific studies, 94% were female.^{18,19,21,22,28,29,31-34,36,38-40,43} Of the non-gender specific studies (43%),^{16,17,20,23-27,30,35,37,42} females comprised the majority of participants in 92% of studies.^{17,20,23-27,30,35,37,42}

Among studies that reported race and/or ethnicity (96%), all comprised a majority of non-Hispanic white participants.^16,18-43

Mindfulness Definition

The investigators did not report a definition of mindfulness in 54% of studies.^{17,18,20,23,27,28,30-34,36-38,40} Of the studies that reported a definition of mindfulness, the most frequently reported was a variation of Jon Kabat Zin’s definition, “mindfulness is commonly defined as awareness that arises through paying attention in a particular way, on purpose, in the present moment, and with nonjudgment.”^{16,21,22,24-26,35,42-44} Definitions of mindfulness also included features of openness,^19,26,39,41 acceptance,^19,26,29,41 and curiosity.^19,41

Mindfulness Measures

Of the 43% studies that measured mindfulness, trait mindfulness measures included: Mindful Attention Awareness Scale,^{16,20,21,36,39,41,42} Five Facet Mindfulness Questionnaire,^{21,24,26,35,43} Multidimensional Assessment of Interoceptive Awareness,⁴⁰ Interpersonal Mindfulness Scale,³⁶ Self-Compassion Scale,²¹ and The Experiences Questionnaire.²¹ State mindfulness measures were not included in any study. Two studies that included a measure of trait mindfulness used multiple measures^21,36 and 3 studies measured frequency of mindfulness practice without state or trait mindfulness.^25,28,29 State or trait mindfulness was not measured in 57% of studies.^{17-19,22,23,25,27-34,37,38}

Mindfulness Delivery

The delivery of mindfulness meditations varied in the trials and can be categorized into 3 different formats: (1) in-person sessions with guidance from an instructor (43%)^{17-22,27,29,40-43}; (2) in-person with provided meditation resources (e.g., CDs, recorded meditations, workbook) for continued at home practice (29%)^{23-25,28,33-35,37}; and (3) online with/without recorded meditations (e.g., video conferencing software, commercially available mindfulness application) (29%).^{16,26,30-32,36,38,39}

Use of Behavioral Theory

The use of behavioral theory to guide the development, implementation, or evaluation of the MBI was reported in only 3 studies.^22,34,37 Behavioral theories included in the studies were the social cognitive theory,^22,37 self-regulation theory,³⁴ and the transtheoretical model.³⁷

Emerging Themes

In addition to most RCTs testing outcomes of MBIs in treatment and survivorship stages, the following 5 themes emerged from the results of this scoping review: (1) inconsistency in defining mindfulness; (2) differences in measuring mindfulness; (3) underrepresentation of racial/ethnic minorities; (4) underrepresentation of males and cancer sites other than breast; and (5) the lack of behavioral theory in the design, implementation, and evaluation of the MBI.

Conclusions

This scoping review assessed the use of MBIs across the cancer continuum that were tested in studies that used a RCT design. Scoping reviews do not assess study bias and effect size, and therefore we are unable to provide study results.^12,13,45 However, our scoping review highlights 5 major themes that will be important to address in future cancer-related research using MBIs.

First, in alignment with previous research, there are significant inconsistencies defining mindfulness in MBIs.⁴⁶ Although Jon-Kabat Zin’s definition of mindfulness or a variation of the definition is commonly reported in reviewed studies, there is minimal transparency regarding the integration of the definition into MBI activities. The lack of the incorporation of mindfulness definitions into MBI activities significantly limits our understanding of the underlying mechanisms of mindfulness, how to evaluate it, and the benefit that individuals may receive from participating in an MBI.⁴⁶

Second, in agreement with previous research, there are significant inconsistencies measuring mindfulness in MBIs.⁴⁶ A comprehensive evaluation of MBIs requires a robust measurement plan including assessment of state and trait mindfulness, in addition to the frequency, duration, and type of mindfulness practice.⁴⁷ The studies included in this review of MBIs across the cancer continuum commonly lacked measures of state and trait mindfulness and/or relied on measures of the frequency and duration of mindfulness practice to serve as a proxy for improvements in the outcomes of interest. The omission of state mindfulness is common due to inherent challenges measuring mindfulness in the moment; however, research should incorporate post-mindfulness questions for participants to reflect on their meditation experience (e.g., Were you distracted during your meditation?). Furthermore, mindfulness as an underlying personality trait may influence participants’ mindfulness experience and may affect psychosocial outcomes of interest.⁴⁸ Therefore, it is essential to measure trait mindfulness to control for a potential confounding variable and to reduce study bias.

Based on these findings, the following recommendations are suggested for defining and measuring mindfulness in future cancer-related studies: (1) include a clear definition of mindfulness; (2) provide a detailed explanation of how features of the mindfulness definition were integrated into mindfulness activities and measurements; and (3) incorporate a robust measurement plan to include measures of state and trait mindfulness in addition to the frequency, duration, and type of mindfulness practice.

Third, racial/ethnic minorities are underrepresented in MBIs across the cancer continuum. It is also important to recognize that cancer health disparities exist by race and ethnicity across the different stages of the cancer continuum.^49,50 Reasons for these disparities include having less access to healthcare, limited health literacy, practicing less healthy behaviors, and having lower cancer screening rates and poorer treatment adherence.^1,49,51 Despite the need to reduce cancer health disparities across the cancer continuum, all studies that reported race and/or ethnicity were comprised of a majority of non-Hispanic white participants.

Fourth, most of the studies were conducted among female breast cancer patients. Previous research has identified potential gender differences in mindfulness practice.⁵² Females are more likely to report engagement in meditation practice; however, males and females report similar perceived benefits.⁵² In the current scoping review, even when excluding MBIs for gender-specific cancers (e.g., breast, prostate), females comprised the majority of participants. Therefore, future research using MBIs should consider having a more balanced and heterogenous sample included in studies. Additionally, future research should explore the use of MBIs in cancer sites other than breast.

Fifth, the use of behavioral theory in the design, implementation, and evaluation of the MBI was rarely reported. Behavioral theories provide the opportunity for researchers to explore the potential underlying mechanisms of MBIs. However, only 3 studies in the current review incorporated behavioral theory.^22,34,37 Future intervention research should use behavioral theory to explore the following areas: (1) common theoretical constructs such as perceived benefits, perceived barriers, and self-efficacy of mindfulness practice; (2) social and contextual factors associated with the integration of mindfulness practice among patients with different race, ethnicities, and genders; (3) application of mindfulness practice to self-regulate negative emotions (e.g., fear, anxiety) before cancer screening and procedures; and (4) initiation and maintenance of mindfulness practice during ongoing cancer treatment and survivorship.

Since targeted MBIs have shown improved outcomes in cancer survivorship and treatment stages,¹¹ there is the potential for MBIs to reduce anxiety among individuals in cancer prevention, detection, and diagnosis stages of the cancer continuum. Prior research supports the association between chronic stress, the immune system, and cancer development and metastasis,⁴ emphasizing the need for stress-management interventions across the cancer continuum. For example, intervention content may incorporate mindfulness to manage stress in addition to the educational components focused on cancer prevention and the importance of early detection by being up-to-date with screening. This example is illustrative since perceived anxiety and stress are common barriers to cancer screening (e.g., colonoscopy, mammogram, Pap test)^53-55 and diagnostic (e.g., biopsy) procedures.⁵⁶ Patient anxiety and stress may result in appointment cancellations/no-shows,⁶ increased procedural time,⁵⁷ decreased patient satisfaction,⁵⁸ and may impact the efficacy of the procedure (e.g., bowel prep adherence and tolerability).⁵⁹ Previous research supports the use of online MBIs,⁶⁰ and may be delivered during the time leading up to the procedure to reduce appointment cancellations/no-shows and may be delivered in the waiting room to reduce procedure time and improve patient satisfaction.

Limitations

The results of the current scoping review of MBIs in cancer-related studies has a few limitations. The current review is not an exhaustive report of MBIs that were used across the cancer continuum. We excluded the etiology and end of life stages to restrict the focus on more relevant comparisons. A second limitation of this review is our narrow definition of cancer prevention. MBIs were only considered in the prevention stage if the purpose of the study was to prevent cancer and not to change a health behavior (e.g., diet, physical activity). Furthermore, the current scoping review was limited to studies reported in English, published during 2000 to mid-2022, and conducted in the United States. In addition, as with all scoping reviews, there is potential for misclassification of studies during the search and selection process. To address this potential limitation, we used 2 independent reviewers with a 92% agreement percentage and all discordant decisions were rectified following discussion.

So What?

What is Already Known on This Topic?

Previous research supports the use of MBIs to improve health outcomes (e.g., anxiety, depression) within the treatment and survivorship stages of the cancer continuum.¹¹ However, there is a potential gap in the scientific literature pertaining to the use of MBIs among individuals in other stages in the cancer continuum (i.e., prevention, detection, diagnosis).

What Does the Article Add?

This scoping review identified the lack of RCTs to assess MBIs in the prevention, detection, and diagnosis stages of the cancer continuum as a gap in research and knowledge. This review also identified 5 themes to guide future research.

What are the Implications for Health Promotion Practice or Research?

Future MBIs may incorporate targeted mindfulness and educational components focused on stress management, cancer prevention, the importance of early detection by being up-to-date with screening, and reducing pre-procedural anxiety before cancer detection/diagnostic procedures.

Footnotes

Author Contributions

Brent Emerson: Conceptualization, Methodology, Data curation, Formal analysis, Writing-original draft, Writing-review & editing, Menaka Reddy: Methodology, Data curation, Formal analysis, Writing-review & editing, Paul L. Reiter: Conceptualization, Methodology, Writing-review & editing, Abigail B. Shoben: Conceptualization, Methodology, Writing-review & editing, Maryanna Klatt: Conceptualization, Methodology, Writing-review & editing, Subhankar Chakraborty: Writing-review & editing, Mira L. Katz: Conceptualization, Methodology, Writing-review & editing.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Brent Emerson

References

Siegel

Miller

Wagle

Jemal

. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17-48. doi:10.3322/caac.21763

National Cancer Institute Division of Cancer Control & Population Sciences . Cancer Control Continuum. https://cancercontrol.cancer.gov/about-dccps/about-cc/cancer-control-continuum

Fletcher

Flight

Chapman

Fennell

Wilson

. The information needs of adult cancer survivors across the cancer continuum: a scoping review. Patient Educ Couns. 2017;100(3):383-410. doi:10.1016/j.pec.2016.10.008

Segerstrom

Miller

. Psychological stress and the human immune system: a meta-analytic study of 30 years of inquiry. Psychol Bull. 2004;130(4):601-630. doi:10.1037/0033-2909.130.4.601

Jeffery

. Relationships between perceived stress and health behaviors in a sample of working adults. Health Psychol. 2003;22:638-642. doi:10.1037/0278-6133.22.6.638

Lacy

Paulman

Reuter

Lovejoy

. Why we don’t come: patient perceptions on no-shows. Ann Fam Med. 2004;2(6):541-545. doi:10.1370/afm.123

Gruszczyńska

Bąk-Sosnowska

Szemik

. Selected psychological aspects and medication adherence in oncological patients. Cancer Med. 2020;9(3):943-950. doi:10.1002/cam4.2691

H-M

Son

C-G

. The risk of psychological stress on cancer recurrence: a systematic review. Cancers (Basel). 2021;13(22):5816. doi:10.3390/cancers13225816

Smith

Gomm

Dickens

. Assessing the independent contribution to quality of life from anxiety and depression in patients with advanced cancer. Palliat Med. 2003;17(6):509-513. doi:10.1191/0269216303pm781oa

10.

Hofmann

Gómez

. Mindfulness-based interventions for anxiety and depression. Psychiatr Clin North Am. 2017;40(4):739-749. doi:10.1016/j.psc.2017.08.008

11.

Cillessen

Johannsen

Speckens

AEM

Zachariae

. Mindfulness-based interventions for psychological and physical health outcomes in cancer patients and survivors: a systematic review and meta-analysis of randomized controlled trials. Psychooncology. 2019;28(12):2257-2269. doi:10.1002/pon.5214

12.

Levac

Colquhoun

O'Brien

. Scoping studies: advancing the methodology. Implement Sci. 2010;5:69. doi:10.1186/1748-5908-5-69

13.

Arksey

O'Malley

. Scoping studies: towards a methodological framework. Int J Soc Res Methodol. 2005;8(1):19-32. doi:10.1080/1364557032000119616

14.

Tricco

Lillie

Zarin

, et al. PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Ann Intern Med. 2018;169(7):467-473. doi:10.7326/m18-0850

15.

Babineau

. Product review: covidence (systematic review software). J Can Health Libr Assoc. 2014;35(2):68-71.

16.

Black

Peng

Sleight

Nguyen

Lenz

H-J

Figueiredo

. Mindfulness practice reduces cortisol blunting during chemotherapy: a randomized controlled study of colorectal cancer patients. Cancer. 2017;123(16):3088-3096. doi:10.1002/cncr.30698

17.

Blaes

Fenner

Bachanova

, et al. Mindfulness-based cancer recovery in survivors recovering from chemotherapy and radiation. J Community Support Oncol. 2016;14:351-358. doi:10.12788/jcso.0244

18.

Bower

Crosswell

Stanton

, et al. Mindfulness meditation for younger breast cancer survivors: a randomized controlled trial. Cancer. 2015;121(8):1231-1240. doi:10.1002/cncr.29194

19.

Bower

Partridge

Wolff

, et al. Targeting depressive symptoms in younger breast cancer survivors: the pathways to wellness randomized controlled trial of mindfulness meditation and survivorship education. J Clin Oncol. 2021;39(31):3473-3484. doi:10.1200/jco.21.00279

20.

Clark

Cortese-Jimenez

Cohen

. Effects of reiki, yoga, or meditation on the physical and psychological symptoms of chemotherapy-induced peripheral neuropathy: a randomized pilot study. J Evid Based Complementary Altern Med. 2012;17(3):161-171. doi:10.1177/2156587212450175

21.

Crane-Okada

Kiger

Sugerman

, et al. Mindful movement program for older breast cancer survivors: a pilot study. Cancer Nurs. 2012;35(4):E1-13. doi:10.1097/NCC.0b013e3182280f73

22.

Henderson

Clemow

Massion

Hurley

Druker

Hébert

. The effects of mindfulness-based stress reduction on psychosocial outcomes and quality of life in early-stage breast cancer patients: a randomized trial. Breast Cancer Res Treat. 2012;131(1):99-109. doi:10.1007/s10549-011-1738-1

23.

Hunter

Maunder

Sui

, et al. A randomized trial of nurse-administered behavioral interventions to manage anticipatory nausea and vomiting in chemotherapy. Cancer Med. 2020;9(5):1733-1740. doi:10.1002/cam4.2863

24.

Johns

Brown

Beck-Coon

Monahan

Tong

Kroenke

. Randomized controlled pilot study of mindfulness-based stress reduction for persistently fatigued cancer survivors. Psychooncology. 2015;24(8):885-893. doi:10.1002/pon.3648

25.

Johns

Brown

Beck-Coon

, et al. Randomized controlled pilot trial of mindfulness-based stress reduction compared to psychoeducational support for persistently fatigued breast and colorectal cancer survivors. Support Care Cancer. 2016;24(10):4085-4096. doi:10.1007/s00520-016-3220-4

26.

Kubo

Kurtovich

McGinnis

, et al. A randomized controlled trial of mHealth mindfulness intervention for cancer patients and informal cancer caregivers: a feasibility study within an integrated health care delivery system. Integr Cancer Ther. 2019;18:1534735419850634. doi:10.1177/1534735419850634

27.

Lehto

Wyatt

Sikorskii

Tesnjak

Kaufman

. Home-based mindfulness therapy for lung cancer symptom management: a randomized feasibility trial. Psychooncology. 2015;24(9):1208-1212. doi:10.1002/pon.3755

28.

Lengacher

Johnson-Mallard

Post-White

, et al. Randomized controlled trial of mindfulness-based stress reduction (MBSR) for survivors of breast cancer. Psychooncology. 2009;18(12):1261-1272. doi:10.1002/pon.1529

29.

Lerman

Jarski

Rea

Gellish

Vicini

. Improving symptoms and quality of life of female cancer survivors: a randomized controlled study. Ann Surg Oncol. 2012;19(2):373-378. doi:10.1245/s10434-011-2051-2

30.

Messer

Horan

Larkey

Shanholtz

. Effects of internet training in mindfulness meditation on variables related to cancer recovery. Mindfulness. 2019;10:2143-2151. doi:10.1007/s12671-019-01182-y

31.

Milbury

Kroll

Chen

, et al. Pilot randomized controlled trial in women with non-small cell lung cancer to assess the feasibility of delivering group-based psychosocial care via videoconference. Integr Cancer Ther. 2021;20:15347354211052520. doi:10.1177/15347354211052520

32.

Millstine

Bhagra

Jenkins

, et al. Use of a wearable EEG headband as a meditation device for women with newly diagnosed breast cancer: a randomized controlled trial. Integr Cancer Ther. 2019;18:1534735419878770. doi:10.1177/1534735419878770

33.

Monti

Kash

Kunkel

, et al. Psychosocial benefits of a novel mindfulness intervention versus standard support in distressed women with breast cancer. Psychooncology. 2013;22(11):2565-2575. doi:10.1002/pon.3320

34.

Monti

Peterson

Kunkel

, et al. A randomized, controlled trial of mindfulness-based art therapy (MBAT) for women with cancer. Psychooncology. 2006;15(5):363-373. doi:10.1002/pon.988

35.

Nakamura

Lipschitz

Kuhn

Kinney

Donaldson

. Investigating efficacy of two brief mind-body intervention programs for managing sleep disturbance in cancer survivors: a pilot randomized controlled trial. J Cancer Surviv. 2013;7(2):165-182. doi:10.1007/s11764-012-0252-8

36.

Price-Blackshear

Pratscher

Oyler

, et al. Online couples mindfulness-based intervention for young breast cancer survivors and their partners: a randomized-control trial. J Psychosoc Oncol. 2020;38(5):592-611. doi:10.1080/07347332.2020.1778150

37.

Rabin

Pinto

Fava

. Randomized trial of a physical activity and meditation intervention for young adult cancer survivors. J Adolesc Young Adult Oncol. 2016;5(1):41-47. doi:10.1089/jayao.2015.0033

38.

Ratcliff

Prinsloo

Chaoul

, et al. A randomized controlled trial of brief mindfulness meditation for women undergoing stereotactic breast biopsy. J Am Coll Radiol. 2019;16(5):691-699. doi:10.1016/j.jacr.2018.09.009

39.

Rosen

Paniagua

Kazanis

Jones

Potter

. Quality of life among women diagnosed with breast Cancer: a randomized waitlist controlled trial of commercially available mobile app-delivered mindfulness training. Psychooncology. 2018;27(8):2023-2030. doi:10.1002/pon.4764

40.

Thomas

Mijangos

Hansen

, et al. Mindfulness-oriented recovery enhancement restructures reward processing and promotes interoceptive awareness in overweight cancer survivors: mechanistic results from a stage 1 randomized controlled trial. Integr Cancer Ther. 2019;18:1534735419855138. doi:10.1177/1534735419855138

41.

Victorson

Hankin

Burns

, et al. Feasibility, acceptability and preliminary psychological benefits of mindfulness meditation training in a sample of men diagnosed with prostate cancer on active surveillance: results from a randomized controlled pilot trial. Psychooncology. 2017;26(8):1155-1163. doi:10.1002/pon.4135

42.

Wirth

Franco

Wagner Robb

, et al. Randomized controlled trial of a 4-week mindfulness intervention among cancer survivors compared to a breathing control. Cancer Invest. 2019;37(4-5):227-232. doi:10.1080/07357907.2019.1610968

43.

Witek Janusek

Tell

Mathews

. Mindfulness based stress reduction provides psychological benefit and restores immune function of women newly diagnosed with breast cancer: a randomized trial with active control. Brain Behav Immun. 2019;80:358-373. doi:10.1016/j.bbi.2019.04.012

44.

Kabat-Zinn

. Mindfulness-based stress reduction (MBSR). Constr Hum Sci. 2003;8(2):73-107.

45.

Munn

Peters

MDJ

Stern

Tufanaru

McArthur

Aromataris

. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Med Res Methodol. 2018;18(1):143. doi:10.1186/s12874-018-0611-x

46.

Davidson

Kaszniak

. Conceptual and methodological issues in research on mindfulness and meditation. Am Psychol. 2015;70(7):581-592. doi:10.1037/a0039512

47.

Sauer

Walach

Schmidt

, et al. Assessment of mindfulness: review on state of the art. Mindfulness. 2013;4(1):3-17. doi:10.1007/s12671-012-0122-5

48.

Vago

Gupta

Lazar

. Measuring cognitive outcomes in mindfulness-based intervention research: a reflection on confounding factors and methodological limitations. Curr Opin Psychol. 2019;28:143-150. doi:10.1016/j.copsyc.2018.12.015

49.

Zavala

Bracci

Carethers

, et al. Cancer health disparities in racial/ethnic minorities in the United States. Br J Cancer. 2021;124(2):315-332. doi:10.1038/s41416-020-01038-6

50.

Williams

Priest

Anderson

. Understanding associations among race, socioeconomic status, and health: patterns and prospects. Health Psychol. 2016;35(4):407-411. doi:10.1037/hea0000242

51.

Islami

Guerra

Minihan

, et al. American Cancer Society's report on the status of cancer disparities in the United States, 2021. CA Cancer J Clin. 2022;72(2):112-143. doi:10.3322/caac.21703

52.

Upchurch

Johnson

. Gender differences in prevalence, patterns, purposes, and perceived benefits of meditation practices in the United States. J Womens Health. 2019;28(2):135-142. doi:10.1089/jwh.2018.7178

53.

Shafer

Walker

Waldman

, et al. Factors associated with anxiety about colonoscopy: the preparation, the procedure, and the anticipated findings. Dig Dis Sci. 2018;63(3):610-618. doi:10.1007/s10620-018-4912-z

54.

Loving

Aminololama-Shakeri

Leung

JWT

. Anxiety and its association with screening mammography. J Breast Imagining. 2021;3(3):266-272. doi:10.1093/jbi/wbab024

55.

O'Laughlin

Strelow

Fellows

, et al. Addressing anxiety and fear during the female pelvic examination. J Prim Care Community Health. 2021;12:2150132721992195. doi:10.1177/2150132721992195

56.

Maimone

Morozov

Wilhelm

, et al. Understanding patient anxiety and pain during initial image-guided breast biopsy. J Breast Imagining. 2020;2(6):583-589. doi:10.1093/jbi/wbaa072

57.

Yang

Sriranjan

Abou-Setta

Poluha

Walker

Singh

. Anxiety associated with colonoscopy and flexible sigmoidoscopy: a systematic review. Am J Gastroenterol. 2018;113(12):1810-1818. doi:10.1038/s41395-018-0398-8

58.

Chartier

Arthurs

Sewitch

. Patient satisfaction with colonoscopy: a literature review and pilot study. Can J Gastroenterol Hepatol. 2009;23(3):203-209. doi:10.1155/2009/903545

59.

Bessissow

Van Keerberghen

C-A

Van Oudenhove

, et al. Anxiety is associated with impaired tolerance of colonoscopy preparation in inflammatory bowel disease and controls. J Crohns Colitis. 2013;7(11):e580-e587. doi:10.1016/j.crohns.2013.04.011

60.

Spijkerman

MPJ

Pots

WTM

Bohlmeijer

. Effectiveness of online mindfulness-based interventions in improving mental health: a review and meta-analysis of randomised controlled trials. Clin Psychol Rev. 2016;45:102-114. doi:10.1016/j.cpr.2016.03.009