Abstract
The 2009 publication “Revised American Thyroid Association Management Guidelines for Patients with Thyroid Nodules and Differentiated Thyroid Cancer” (1), referred to here as “ATA guidelines,” is followed worldwide by a great number of physicians. The subsection “Surgery for a biopsy diagnostic for malignancy” starting on page 1178 discusses the extent of thyroid surgery required for differentiated thyroid carcinoma (DTC). Respectfully, we disagree with some of the recommendations in this section.
On page 1179 of the ATA guidelines it is stated that older age (>45) may be also a criterion for recommending near-total or total thyroidectomy even with tumors <1–1.5 cm, because of the higher recurrence rates in this age group. References 112 by van Heerden et al. (2), 116 by Hay et al. (3), 122 by Hay et al. (4), 123 by Lin et al. (5), and 157 by Rubino et al. (6) are provided (1) in support of this. However, most of the cited references do not support this suggestion. Reference 112 by van Heerden et al. (2) analyzed the cause-specific mortality not the recurrence rates and suggested that for follicular thyroid carcinoma the dominant determinant of cause-specific mortality was the presence of distant metastases at diagnosis. They found that age ≥50 did not significantly increase the cause-specific mortality (p=0.42), and did not make any suggestion about the extent of surgery for DTC. Reference 116 by Hay et al. (3) analyzed the risk factors for predicting survival in 1779 patients with papillary thyroid carcinoma (PTC) and introduced the MACIS scoring system (named for its predictive variables of Metastasis, Ages, Completeness of surgical excision, local Invasion, and tumor Size). This article does not mention recurrence. Age is an important component of the MACIS prognostic scoring system. Besides, there was no suggestion of near-total or total thyroidectomy specifically for patients >45 years with tumors <1–1.5 cm. Based on the referenced article 116 by Hay et al. (3), there are no data or conclusions that age >45 should be a criterion for total thyroidectomy in patients with a tumor <1–1.5 cm. Reference 122 by Hay et al. (4) analyzed 2444 patients with PTC treated at Mayo Clinic during six decades and found that radioactive remnant ablation (RRA) in patients with low-risk tumors with MACIS scoring of <6 was of no benefit for survival. Ten-year survival for PTC with MACIS <6 was 100%, and this cannot be improved by RRA. They also showed that according to time trends near-total or total thyroidectomy improved survival and recurrence in low-risk and high-risk patients with PTC compared to lobectomy. However, there are no data presented or conclusions drawn that older patients with tumors <1–1.5 cm are at increased risk for recurrence, nor any specific suggestion of total or near-total thyroidectomy for these patients. Low-risk PTC patients with MACIS score <6 may include younger or older patients with tumors of any size and tumors with or without local invasion and incomplete excision. Therefore, from the finding that total or near-total thyroidectomy decreases recurrence in patients with low-risk MACIS score, it cannot be inferred that older patients (>45) with tumors <1–1.5 cm should undergo total thyroidectomy. Reference 123 by Lin et al. (5) did not make any suggestion that older patients (>45) with tumors <1–1.5 cm had a high risk of recurrence. Reference 157 by Rubino et al. (6) reported on 576 second primary malignancies in thyroid cancer patients. It did not state the risk of recurrence or on the extent of thyroidectomy in older patients with tumors <1–1.5 cm. On page 1779 of the ATA guidelines it is stated that “increased extent of primary surgery may improve survival for low-risk patients.” Reference 156 by Bilimoria et al. (7) is provided in support of this. However, this is not supported by the findings of the Bilimoria et al. study (7). In the Bilimoria et al. study (7) the information regarding the histology of tumor, the status of extrathyroid extension, and the completeness of resection are missing (8). Therefore, this study lacks of information for assessment of risk of recurrence for low-risk patients defined by the subsection B13 of the ATA guidelines (1) on page 1180, and it is not appropriate for supporting the suggestion that the increased extent of surgery may improve survival for low-risk patients. On page 1779 of the ATA guidelines (1) it is stated that “other studies have also shown that rates of recurrence are reduced by total or near-total thyroidectomy among low-risk patients.” Reference 122 by Hay et al. (4), reference 161 by Shaha et al. (9), and 162 by Sanders and Cady (10) are provided in support of this statement. As we stated previously regarding reference 122 by Hay et al. (4) considering the time trends they showed that near-total or total thyroidectomy improved survival and decreased recurrence in low-risk and high-risk patients with PTC compared to lobectomy. Reference 122 by Hay et al. supports the suggestion that rates of recurrence are reduced by total or near-total thyroidectomy among low-risk patients by the ATA guidelines (1). Reference 161 by Shaha et al. (9) stated in contrast to the guidelines statement that “there was essentially no survival difference in patients below or above the age of 45 in this series.” The authors did not make any suggestion that rates of recurrence are reduced by total or near-total thyroidectomy among low-risk patients. Guidelines stated that rates of recurrence are reduced by total or near-total thyroidectomy among low-risk patients (1). However, reference 162 by Sanders and Cady (10), contrary to the statement, concluded that bilateral thyroidectomy compared with unilateral thyroidectomy did not significantly decrease recurrence rates nor improve survival among low-risk patients as well as high-risk DTC. In conclusion, in the subsection of ATA guidelines (1) ([B8] Surgery for a biopsy diagnostic for malignancy, pp. 1178–1179), most of the cited references either do not address or do not support the suggested opinions. We propose that this subsection should be rewritten considering our evaluations.