Thyroid cancer and thyroid nodules in acromegaly: a single-center retrospective study

PURPOSE: To evaluate the incidence and progression of thyroid nodules and cancers in acromegaly and the necessity for increased surveillance. METHODS: This retrospective study identified 1075 acromegaly patients who underwent thyroid ultrasounds from 1830 consecutive cases between 2013 and 2022 at a single center. Thyroid nodules were assessed using the American College of Radiology Thyroid Imaging Reporting and Data System. Control data were from 17839 individuals who received thyroid ultrasounds at a health screening center during the same period. RESULTS: In 1830 acromegaly patients, 80 thyroid cancers (4.4, 82.5% females) were reported, mainly papillary, except 1 follicular and 1 medullary cancer. Thyroid nodules were found in 765 (71.2%) acromegaly patients at baseline, more than in the control (43.7%, p < 0.001). Nodule size in acromegaly was slightly larger (0.7 [0.5, 1.2] vs. 0.5 [0.4, 0.9]cm, p < 0.001). During a 3.9 ± 2.6-year follow-up, new thyroid cancers in acromegaly were mainly confirmed in previously high-risk nodules. Among 339 acromegaly patients with follow-up ultrasound, 57 (16.8%) confirmed new thyroid cancers or nodular growth over 2.8 ± 2.3 years, compared to 10.8% (302/2796) in controls with a shorter follow-up (1.0 [0.9,1.1] years). During this short interval, no difference in growth hormone or insulin-like growth factor 1 levels was observed in acromegaly patients with newly diagnosed thyroid cancers. CONCLUSION: Thyroid nodules are more common in acromegaly, but whether thyroid cancer risk is increased remains uncertain. Given the potential overdiagnosis, our data do not support routine baseline thyroid ultrasound screening, and thyroid nodule surveillance may follow risk-stratified recommendations in the general population.