Risk factors for well-differentiated thyroid cancer in men

Thyroid cancers are relatively rare tumors that appear more frequently in women than in men. Accordingly, most studies focus on studying risk factors for thyroid cancer in women and consequently on various hormonal or reproductive factors that are specific for women. The aim of our study was to examine risk factors for developing well-differentiated thyroid cancer in men. Heretofore, we did not encounter in the literature a study that was solely focused on studying risk factors for well-differentiated thyroid cancer in men.

A case-control study was performed from 2005 to 2010. The case group included 204 consecutive well-differentiated thyroid cancers in male patients (180 papillary and 24 follicular including Hürthle cell). The control group comprised the same number of cases. Patients were individually matched by gender, age and place of residence. Statistical analysis included conditional univariate and multivariate logistic regression methods.

According to univariate logistic regression, well-differentiated thyroid cancer in men was significantly related to smoking status, duration of smoking, number of cigarettes smoked per day, history of goiter or thyroid nodules, history of non-thyroid cancer, diabetes mellitus, radiotherapy of the head and neck, and history of malignant tumors. According to multivariate logistic regression, it was independently related to smoking status (OR = 0.36; 95% CI, 0.19-0.69), history of goiter or thyroid nodules (OR = 9.19; 95% CI, 1.25-64.58), and a history of malignant tumors (OR = 2.11; 95% CI, 1.19-7.33).

Risk factors for well-differentiated thyroid cancer in men were goiter or thyroid nodules and family history of malignant tumors. Cigarette smoking was negatively associated with the disease.