Bone and Soft Tissue Sarcoma Epidemiology in Iranian Elderly Population; an Analysis of the Iranian National Registry for Cancer (2009-2014 Years).

Background: We aimed to investigate the patterns of incidence and prevalence of bone sarcoma (BS) and soft tissue sarcoma (STS), morphology as well as geographical distribution in the elderly in Iran. Methods: By the primary site of the tumor and the morphological types, whole cases of cancer were classified. Then, the WHO classification (2018) and the third revision of the standard International Classification of Diseases for Oncology (ICD-O-3) were used to assign a code to them. The estimated incidence rates were obtained as the frequency of the newly-diagnosed cases within one year divided by the calculated population of the mid-year Iranian residents as estimated by the Iranian Bureau of Statistics. The age-standardized incidence rates were also estimated for both bone and soft tissue sarcoma. Results: The annual crude incidence rates of sarcomas in males (0.80 per 100,000) were more than in females (0.55 per 100,000) in all years. The total combined crude incidence in 2014 years was obtained at 0.67 per 100,000 people. In terms of disease grade majority of the patients were of grade 3 (11.5 %). In terms of tumor location, the Lower extremity was 16.8%, the Visceral (including gastrointestinal & uterus) 15.8%, the Thoracic 12.8%, and the Pelvic & abdominal wall 9.7%. Conclusion: Even though such sarcoma is more prevalent in elderly men, its incidence was also observed in lower-aged female groups. In addition, the incidence rate of BS was lower in comparison with that of STS, and the patients often exhibited an unknown degree of sarcoma.