Prognostication in soft tissue sarcoma. A model with four risk factors.

A multivariate analysis of risk factors for death due to tumor was performed in 82 patients with highly malignant, histologic Grades III and IV primary soft tissue sarcoma of the locomotor system. All the patients had been operated on with a wide or radical surgical margin. Male sex, histologic malignancy Grade IV, extensive tumor necrosis, and tumor size greater than 10 cm were identified as risk factors. Patients with no or one risk factor had a 6(10)-year survival rate of 100% (100%), equal to 96% (96%) in a group with Grade I and Grade II tumors operated on with the same margin. These two groups comprised 50% of all the patients operated on with a wide or radical margin. The 6(10)-year survival rate decreased to 75% (75%) for patients with two risk factors and to 33% (22%) for patients with three or four risk factors. The risk factor model also applied to 62 patients operated on with marginal surgery; and for patients with three or four risk factors, more extensive surgery only had a small effect on long-term survival. The model could be of value when eligibility criteria for trials with adjunctive chemotherapy are determined.