Prognostic factors in retroperitoneal sarcoma: a multivariate analysis of a series of 165 patients of the French Cancer Center Federation Sarcoma Group

BACKGROUND: Surgery is the main prognostic factor in retroperitoneal sarcoma. However, despite progress, surgery alone is rarely curative, and analysis of the causes of failures and of other prognostic factors are warranted to ascertain treatment orientations. METHODS: Data of patients treated from 1.80 to 12.94 for primary retroperitoneal sarcoma were extracted from the French Federation of Cancer Centers Sarcoma Group registry. Univariate and multivariate analysis were performed for initial local control and for local and general outcome. One hundred sixty-five patients (median age, 54 years; range, 16--82 years) were identified. Median tumor size was 15 cm (range, 2--70 cm); 31% of tumors presented with neurovascular or bone involvement. Liposarcoma, leiomyosarcoma, and malignant fibrous histiocytoma represented 66% of the tumors. Eighty-four percent of the tumors were of high or intermediate grade. Twenty patients had initial metastases. Multimodality treatment included surgery (150 patients), radiotherapy (92 patients), and chemotherapy (77 patients). Complete excision was achieved in 94 of 145 nonmetastatic patients. Median follow-up was 47 months (range, 3--160 months). RESULTS: Actuarial overall 5-year survival rate (median) was 46% (51 months). The main prognostic factors for survival were initial metastases and surgery, which represented the major treatment-linked factor. High-grade of tumors affected local recurrence, metastatic recurrence, and survival. Adjuvant radiotherapy was significantly associated with reduced local recurrence. Various evolutive patterns were observed with histologic subtypes. CONCLUSIONS: Aggressive surgery remains mandatory in retroperitoneal sarcoma, but a randomized trial is needed to evaluate the place of radiotherapy for local control.