Thyroid cancer: zealous imaging has increased detection and treatment of low risk tumours.

Thyroid cancer is the most common endocrine malignancy. Worldwide, its incidence has increased substantially over the past 50 years. The Cancer Incidence in Five Continents report showed that the age standardised incidence of thyroid cancer in women rose from 1.5 cases/100 000 population in 1953 to 7.5 cases/100 000 in 2002, with a similar relative increase in men (fig 1⇓). Behind these averages hide important and surprising differences between and within countries. In the US, the incidence of thyroid cancer has tripled in the past 30 years, increasing from 3.6 cases/100 000 in 1973 to 11.6 cases/100 000 in 2009, making it one of the fastest growing diagnoses. By contrast, in Sweden, Japan, and China, the increase in incidence has been minimal. Not all thyroid cancers are equal