Survival of thyroid cancer and social determinants in Iran, 2001-2005.

BACKGROUND Thyroid cancer is the most common endocrine system malignancy in the world, being the 7th most common cancer in females, 14th in males and 11th in both sexes in the Iranian population. The present study aimed to determine survival of thyroid cancers in Iran based on sex, age group, pathology and geographical location. METHODS The patients selected for this study were 602 out of 5,759 cases listed in the cancer registry system between 2001 and 2005. The Kaplan-Meier method was used for survival estimation and Cox's proportional hazard model for calculating hazard ratios according to demographic and risk variables. RESULTS The overall 5-year survival rate was 88.0%. There was a significant difference between survivals of the two sexes. The best and worst survival were in the age groups under 40 and over 60 years old, respectively. The best survival was for papillary type, with the anaplastic type demonstrating the worst survival. The best survival was in the southwest (Khuzestan) and the worst in the northwest (Azarbaijan). CONCLUSION Size of young population and social determinants may be important effective elements for differences in survival, which should be taken more into consideration in managing chronic disease such as thyroid cancer.