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.