Adult Pelvic Sarcomas: A Heterogeneous Collection of Sarcomas?

Introduction. Adult pelvic soft tissue sarcomas are a rare group of heterogeneous malignancies. These sarcomas differ from extremity and trunk soft tissue sarcomas in presentation, characteristics and response to treatment. Methods. A retrospective analysis of patient and tumor characteristics, treatment and prognosis and prognostic factors was performed. Results. Between 1977 and 1997, a total of 33 adult patients with soft tissue sarcomas involving the pelvis but excluding uterine leiomyosarcoma were identified. Leiomyosarcomas (18), including six GIST, and rhabdomyosarcomas (eight) were the most commonly seen tumors. At first presentation, nine patients already had metastases. The mean follow-up was 52 months (1–200). Recurrences developed in 15 of the 24 cases (63%) with tumors without metastases at first presentation; in six (25%) recurrence was locally only, in nine distant metastases occurred. The nine patients with metastatic disease at first presentation died of the disease, while eight of the 24 patients with localized disease at presentation died. One patient died of an unrelated cause, four were alive with disease, and 11 patients were alive and free of disease. The only identifiable prognostic factor of disease-free interval and overall survival was histological grade. Conclusion. Soft tissue sarcomas of the pelvis appear to be associated with increased rate of metastasis at the time of diagnosis and higher rates of local recurrence. In this study, multi-modality treatment for most primary tumors did not show a significant benefit in recurrence rate, DFI and OST, when compared to single modality approach. Although the number of patients in this study is small, and different types of sarcomas were studied, the only identifiable predictor for survival was low histological grade of the tumors. The differences of this heterogeneous group of pelvic sarcomas with retroperitoneal, trunk and extremity sarcomas should be taken into consideration in the management of these sarcomas.