Cancer in Canada Fact Sheet Series #1 Thyroid cancer in Canada

More than 4000 Canadians were diagnosed with thyroid cancer in 2007, or nearly 12 per 100 000, accounting for approximately 2.5% of all malignant tumours. Unlike most cancers, thyroid cancer is three times more common in females than males and is generally diagnosed at a younger age (Figure 1). Nearly 40% of all thyroid cancers are diagnosed before 45 years of age and three-quarters before age 60. Thyroid cancer ranks second in Canadians aged 15 to 44 years (Figure 2) and is the most common cancer diagnosis in those aged 15 to 29 years (Figure 3). The large majority of thyroid cancers are papillary carcinomas (86%), while others include follicular (6%), medullary (2%), anaplastic (1%) and other/unknown (5%). Trends in incidence and mortality