Epidemiology of soft tissue sarcomas in Karachi South, Pakistan (1995-7)

Introduction: The present study was conducted with the objective of examining epidemiological characteristics of soft tissue sarcomas (STSs) in Karachi. Patients and methods: Epidemiological data of 96 (63 male and 33 female) incident STS cases registered at Karachi Cancer Registry (KCR) for Karachi South (KS), from 1st January 1995 to 31st December 1997, were reviewed. Results: The age standardized rate (ASR) world per 100,000 were 3.3 (2.9%) and 2.1 (1.6%) in males and females, respectively, with mean ages of of 41.4 years (95% CI 35.77; 46.97) and 40.2 years (95% CI 31.27; 49.03). The age-specific curves showed a gradual increase in risk from the first until the eighth decade in both genders, with the highest peak at 75+ in females and 70-74 years in males. In males, 8 (12.7%) STS cases were diagnosed in the pediatric age group (0-14), 12 (19.1%) in adolescents and young adults (15-24 years), 19 (30.1%) in adults 25-49 years of age and 24 (38.1%) in the 50 years+ age group. In females the respective frequencies were 11%, 26%, 30% and 33%. The most common histological tumor was rhabdomyosarcoma, though the occurrence of the histological subtypes was age-dependent. Rhabdomyosarcomas and Ewing's sarcomas were more frequent in children and adolescents whereas fibrosarcomas, leiomyosarcomas, liposarcomas, malignant fibrous histiocytomas (MFHs) and schwannomas were encountered in the elderly. Conclusion: Karachi falls into a high risk region for STS, observed in a relatively younger population, with a male predominance, high frequency of rhabdomyosarcoma and advanced stage at diagnosis. Information on grading and staging remain incomplete for most cases, which negatively affect disease management and survival.