Sarcomas Epidemiology in Iran: Analysis of Data from Iranian National Cancer Registry between 2009 and 2014

Background: Sarcomas are a wide group of tumors with a mesenchymal origin, accounting for 1% of all adult malignancies. Objectives: This study examined the incidence rates and distribution patterns of morphological subtypes and primary sites of soft tissue and bone sarcomas in a 6-years period in the total population of Iran. Methods: The data was retrieved from the Iranian National Cancer Registry (INCR). A total of 14630 patients were identified with either bone or soft tissue sarcoma during 2009 - 2014. The morphological and topographical classifications were based on the ICD-O-3 and World Health Organization (WHO) guidelines. The crude and age-standardized incidence rates (ASIR) were calculated. Results: The combined crude incidence was calculated 3.2/100,000, and for STS and BS was 2.7 and 0.5 per 100,000 individuals, respectively, increasing with the age. Among the patients, 16.47 and 83.53% of cases had BS and STS, respectively with male predilection. The ASIR calculated 2.8 and 2.6 for STS and 0.51 and 0.37 for BS in males and females, respectively. Sarcoma, osteosarcoma, leiomyosarcoma, liposarcoma, and spindle cell sarcoma were the most common morphologies. The connective tissue of the lower limb, long bone of the lower limb, skin, and uterus were the most frequent primary tumor sites. The majority of tumors were of unknown/undifferentiated grade (grade 9), then grade 3, 1, 2, 4, and score 0 had the highest frequencies, respectively. The highest ASIR of sarcoma was detected in Khuzestan, Kohgiloyeh and Boyer-Ahmad, Isfahan, Tehran, Fars, and Khorasan Razavi provinces. Analysis of the incidence trends showed a slight increase over the study period. Conclusions: These findings can help better diagnose and management of sarcoma patients throughout Iran.