SOFT TISSUE SARCOMAS OF THE PELVIS

Abstract

99 patients with new diagnosed soft tissue sarcomas involving the pelvic region were studied to determine the outcome and prognostic factors for survival and local recurrence.

The mean age at diagnosis was 57 years. There were 55 males and 44 females. The mean tumor size was 12cm. The tumor was deep in 79 patients and superficial in 20. Surgical treatment was excision in 93 patients and hindquarter amputation in 6 patients. Histological grade was low grade in 23 and high grade in 75 patients. 7% of the patients had metastases at presentation.

The 5 year overall survival was 57% and local recurrence occurred in 22% of the patients. The risk of inadequate surgical margins in patients with tumors within the pelvic brim was 50% compared to 18% for those with tumors located outside the pelvic brim. The significant predictors of local recurrence were inadequate margins and location of the tumor within the pelvic brim. Tumor size, grade and depth did not influence development of local recurrence. Significant predictors of survival included metastases at presentation, tumor grade and depth. The cumulative 5 year survival for patients with deep high grade tumors, deep low grade tumors, superficial high grade and superficial low grade tumors were 45%, 74%, 63% and 100% respectively (p=0.01). The 5-year overall survival was 66% in those patients without local recurrence compared to 37% in those who develop local recurrence (p=0.005). Multivariate analysis revealed that development of local recurrence was the most important determinant of overall and metastases free survival.

We conclude that patients with pelvic soft tissue sarcoma who develop local recurrence have an extremely poor prognosis. Patients with high grade and inadequate surgical margins represent a particular group with very high risk of metastases and death even with radiotherapy and perhaps should be considered for other adjuvant treatment.