Endocrine cancer in Iran: based on cancer registry system.

BACKGROUND: A population-based registry of endocrine cancer cases in four Iranian provinces, was performed for the years 1996-2000. MATERIALS AND METHODS: Patients in each province were grouped according to age, gender and tumor specifics (site, morphology, behavior) and the data was coded according to the international classification of diseases for oncology. STATISTICAL ANALYSIS USED: Person-years of population at risk were calculated and the results were presented as incidence rates by sex, age, age specific rates and age standard rate (ASR) per 100,000 person-years, using direct method of standardization to the world population. RESULTS: A total of 319 cases of primary endocrine cancer were found and registered, including 313 cases of thyroid carcinoma and 6 cases of adrenal cancer. The thyroid carcinoma group cases consisted of papillary (82.7%), follicular (8.6%), medullary (7.0%) and anaplastic (1.6%) carcinomas. The ASR for thyroid carcinoma was 1.289 (0.627 for men, 1.59 for women), with the highest incidence rate in Kerman (ASR 1.643) and the lowest incidence rate in Golestan (ASR 0.735). For the 6 cases of adrenal cancer, 4 were neuroblastoma and 2 were pheochromocytoma. CONCLUSIONS: Iran was considered as an endemic, iodine-deficient area, until fairly recently. Iodinization of salt has been started about 12 years ago, in the nation. Considering the effect of improvement in the iodine intake in previously deficient communities, which is associated with an increase in the incidence of papillary carcinoma compared to other histologic types, the frequency and distribution of histologic types of thyroid carcinoma was closer to what can be seen in iodine-rich areas.

Epidemiologic analysis of the Tehran Cancer Institute Data System Registry (TCIDSR).

OBJECTIVE: To review epidemiological data on thyroid cancer in Iran. METHODS: The Tehran Cancer Institute Data System Registry (TCIDSR) was used to identify patients with different histological types of thyroid cancer (TC) in Iran. Data were analysed from 438 thyroid cancer cases identified by the TCIDSR in 1998-99. Disease prevalence was calculated with reference to age, time and place. RESULTS: The TCIDSR recorded 438 primary malignancies of the thyroid gland: papillary, follicular, medullary, and anaplastic carcinomas accounted for 67.1%, 10.7%, 5.3% and 4.3% of cases, respectively. The remaining 12.6% were classified as OD (other diagnoses). The prevalence of TC was highest in ethnic Farsis. The age range of patients was 8-85 years. Mean patient age was 44.52+17.03 years (mean + SD) overall, 47.74+18.10 years in female patients and 43.04+16.34 years in male patients. Anaplastic (6.5% vs. 3.3%) and medullary (10.0% vs. 3.0%) cancers were more common in men than women. CONCLUSION: This study was undertaken to define the epidemiological aspects of thyroid carcinoma in Iran, an area of endemic iodine deficiency until fairly recently. Against expectation for an iodine-deficient area, the frequency distribution of tumours in our study was closer to that seen in iodine-rich areas. Additional research on the risk factors for thyroid cancer--genetic, ethnic, geographic and environmental--is needed to explain the high incidence of PTC overall, and among ethnic Farsis in particular, in Iran.