Primary malignancies of the thyroid: epidemiologic analysis of the Florida Cancer Data System registry.

PURPOSE

Descriptive epidemiology of thyroid cancer in Florida.

METHODS

The Florida Cancer Data System (FCDS) registry was used to identify patients with the different histologic subtypes of thyroid cancer occurring in Florida from 1981 through 1993.

RESULTS

The FCDS recorded 5746 primary malignancies of the thyroid. The average annual incidence of all types of thyroid cancer was 37.0 cases/1,000,000 population. One type of thyroid cancer (papillary carcinoma) accounted for the overall increase during the 13 years of this study. There was no difference in incidence based on Hispanic ethnicity, but the incidence in Blacks was half that of Whites, and Blacks showed less advanced disease at the time of diagnosis.

CONCLUSIONS

The increase in incidence of only one histologic type of thyroid cancer suggests that the increasing rate is not an artifact related to the utilization of new diagnostic technologies. The lower incidence and tendency to have less advanced thyroid cancer in Blacks would indicate that racial differences in thyroid cancer are not likely explained by socioeconomic factors such as access to medical care. A substantial amount of the difference in incidence between Whites and Blacks is explained by differences in age distribution.