Letter to the Editor: Molecular Testing: Adoption and Disparities in Utilization Across the United States

Dear Editor:

We read with great interest the article by Huang et al. evaluating adoption of molecular testing in the United States (U.S.). ¹ Their study provides valuable insights into trends in the use of molecular testing and its correlation with thyroidectomy rates. To our knowledge, their study is the first to characterize molecular testing utilization nationally, finding that use has dramatically increased from 0% to over 10% in some parts of the country in the past decade. However, this increase in molecular testing performance has not been universal across all populations in the U.S., as black, elderly, rural, and Medicaid insured patients are significantly less likely to undergo molecular testing. These results are important for describing the real-world utilization of molecular testing and its impact on patient care.

We were interested in their finding that, across the U.S., older adults (aged 65–91 years) were less likely to receive molecular testing. This finding is of particularly importance because elderly patients face increased prevalence of thyroid nodules and unique treatment challenges, including a greater burden of comorbidities and increased surgical risks. ² However, a drawback of the database used, MarketScan, is that it is limited to privately insured patients, and only 32% of older adult Medicare beneficiaries have additional coverage through an employer. ³ Therefore, it is possible the results would change if a Medicare population were examined.

Molecular testing is a useful preoperative tool for risk stratification of indeterminate nodules and potentially avoiding surgery with diagnostic lobectomy. As Huang et al. demonstrated, over the study period, rates of thyroidectomy decreased, a finding that was similar in states with both high- and low-adoption of molecular testing. Interestingly, the study included thyroidectomy procedures performed via a sternal or cervical approach and with a radical neck dissection (CPT 60270, 60271, 60254). The extent of resection performed in these thyroidectomy procedures suggests that preoperative molecular testing in these patients may represents overuse of the technology, as they likely already had an indication for surgery regardless of the molecular testing result. ⁴ Further understanding of molecular testing utilization by extent of thyroidectomy performed could detect areas of potential unnecessary use.

The disparities in access to and increasing performance of molecular testing across the U.S. highlighted in this study underscore the need for further research. Data are needed to understand and characterize molecular testing utilization broadly at the national-level as well as on the individual-level focusing on patients’ experiences and the role of molecular testing in clinical decision-making. Filling these knowledge gaps is crucial given the significant burden of indeterminate thyroid nodules identified in up to 30% of biopsies. ⁵ Ultimately, understanding the real-world impact of molecular testing on patient care and outcomes is essential for optimizing the management of patients with indeterminate thyroid nodules. Huang et al. have laid the foundation for this important, ongoing work.