Prognostic factors in retroperitoneal sarcomas: ploidy of DNA as a predictor of clinical outcome.

BACKGROUND AND OBJECTIVES: Radical surgery is the best mode of treatment of retroperitoneal sarcomas (RS); however, common recurrences are unpredictable. METHODS: For the better understanding of outcomes and possibilities of treatment retrospective analysis of different factors, including DNA content, was performed based on 70 patients. RESULTS: Leiomyosarcoma and liposarcoma were most common histologic types of classified sarcomas. Different kinds of resection were successfully performed in 51 patients (73%) and 35 of their available DNA specimens were analyzed. The actuarial 5- and 10-year survival rates in the resection group were 53% and 40%, respectively, with the median survival of 57 months. Patients with diploid resected tumors had a better 10-year survival rate (58%), than those patients with aneuploid tumors (25%,)--P<0.005. Those patients with low-grade sarcomas had a significantly longer survival than those with high-grade sarcomas (10-year survival rate: 44% compared to 29%). In the univariate analysis, adjuvant therapy, type of histology, type of surgery, location of tumor, and S-phase fraction had no influence on survival. In the multivariate analysis (Cox), only ploidy was an independent prognostic variable. Relative risk of death was over three times higher for aneuploid than for diploid tumors. CONCLUSION: Tumor ploidy should be analyzed in every case of retroperitoneal sarcoma for better assessment of prognosis and possible indication for adjuvant therapy.