Risk factors for thyroid cancer

Four hundred out of 513 patients with thyroid cancer presented to Alexandria University Hospital between 1978 and 1990 were valid for the present analysis for the determination of the possible risk factors associated with occurrence of this type of cancer. In the present work the following possible risk factors were studied: Past history of previous head and neck radiation therapy, especially with doses ranging between 3500 and 6400 cGy, past history of goiter and thyrotoxicosis, family history of thyroid carcinoma, especially with the medullary type, low iodine diet associated with all types mainly follicular cancer, high iodine diet associated with higher incidence of papillary and mixed types. The recognition of these possible risk factors and others, with their avoidance are of great importance in attempt of lowering the incidence of this type of cancer