Background: Current guidelines recommend against thyrotropin (TSH) suppression in low-risk differentiated thyroid cancer patients; however, physician practices remain underexplored. Our objective was to understand treating physicians' approach to TSH suppression in patients with papillary thyroid cancer. Methods: Endocrinologists and surgeons identified by thyroid cancer patients from the Surveillance, Epidemiology, and End Results registries of Georgia and Los Angeles were surveyed in 2018-2019. Physicians were asked to report how likely they were to recommend TSH suppression (i.e., TSH <0.5 mIU/L) in three clinical scenarios: patients with intermediate-risk, low-risk, and very low-risk papillary thyroid cancer. Responses were measured on a 4-point Likert scale (extremely unlikely to extremely likely). Multivariable logistic regressions were performed to determine physician characteristics associated with recommending TSH suppression in each of the aforementioned scenarios. Results: Response rate was 69% (448/654). Overall, 80.4% of physicians were likely/extremely likely to recommend TSH suppression for a patient with an intermediate-risk papillary thyroid cancer, 48.8% for a patient with low-risk papillary thyroid cancer, and 29.7% for a patient with very low-risk papillary thyroid cancer. Surgeons were less likely to recommend TSH suppression for an intermediate-risk papillary thyroid cancer patient (odds ratio [OR] = 0.36 [95% confidence interval, CI, 0.19-0.69]) compared with endocrinologists. Physicians with higher thyroid cancer patient volume were less likely to suppress TSH in low-risk and very low-risk papillary thyroid cancer patients (i.e., >40 patients per year, OR = 0.53 [CI 0.30-0.96]; OR = 0.49 [CI 0.24-0.99], respectively, compared with 0-20 patients per year). Physicians who estimated higher likelihood of recurrence were more likely to suppress TSH in a patient with very low-risk papillary thyroid cancer (OR = 2.34 [CI 1.91-4.59]). Conclusions: Many patients with low-risk thyroid cancer continue to be treated with suppressive doses of thyroid hormone, emphasizing the need for more high-quality research to guide thyroid cancer management, as well as better understanding of barriers that hinder guideline adoption.
Keywords: TSH suppression; physician survey; thyroid cancer.