Some of the more recognized risk factors for thyroid cancer include: 1. female 2. age 45 years or older 3. smoking 4. goiter, thyroid nodules 5. previous history of malignancy Some other factors such as autoimmune thyroid disease (e.g. Hashimoto’s thyroiditis), subclinical hypothyroidism, and long-term estrogen replacement are also considered to potentially increase the risk of thyroid cancer. In other words, people with these characteristics are more or less likely to develop thyroid cancer. Fortunately, e.g. women and Hashimoto’s thyroiditis, while increasing the incidence of thyroid cancer, suggest instead a better relative treatment outcome.