OBJECTIVETo investigate the association between serum TSH concentration and thyroid cancer incidence.

METHODSThree hundred and thirty patients with thyroid tumors who underwent surgical treatment were included in this study (99 cases of malignancy and 231 cases of benign tumors). The data of their serum TSH level, gender, age, tumor type, and number of tumors detected by ultrasonic inspection were retrospectively analyzed, and their association with thyroid cancer incidence was explored.

RESULTSThe proportion of thyroid cancer in the groups of younger than twenty years and older than seventy years were 63.0% and 58.3%, respectively, significantly higher than that in the group of age between 60 and 69 years (23.3%, P < 0.05). The incidence of thyroid cancer of the 81 male patients was 43.2%, significantly higher than that in the 249 female patients (25.7%, P = 0.003). The incidence of thyroid cancer in the 112 patients with single nodule was 42.0%, significantly higher than that in the 218 patients with multiple nodules (23.9%, P < 0.001). In the groups with TSH level lower than 0.28 mIU/L and higher than 4.20 mIU/L, the incidence of thyroid cancer were 54.6% and 50.0%, respectively, significantly higher than that in the group with TSH level between 0.28 and 1.44 mIU/L (16.1%, P < 0.05). The proportion of patients with thyroid cancer was also increased with the increasing serum TSH level in the normal range (P < 0.001). High serum TSH level (OR = 1.465, P = 0.014), male (OR = 1.964, P = 0.016) and a single thyroid nodule (OR = 2.090, P = 0.006) are independent risk factors of thyroid cancer.

CONCLUSIONThe high serum TSH level, male, single thyroid nodule are factors leading to a high incidence of thyroid cancer.