OBJECTIVE: To evaluate the frequency of thyroid cancer and thyroid dysfunction in first-degree relatives of thyroid cancer patients, and to determine if there is a difference between familial and sporadic thyroid cancer. SUBJECTS AND METHODS: Fifteen first-degree relatives of seven families with at least two family members with thyroid cancer (TC) were compared with 128 first-degree relatives of 45 families with only one family member affected. Laboratory and ultrasound evaluation, fine-needle aspiration biopsy and thyroid surgery were used as normally […]