Limb-preserving treatment for soft tissue sarcomas of the extremities. The significance of surgical margins.
Between 1970 and 1990, 74 patients with extremity soft tissue sarcomas began a regimen of limb-sparing surgery and irradiation. Ninety-two percent received postoperative irradiation, 7% received preoperative irradiation, and one patient was treated with radiation after an incisional biopsy only. Radiation was administered with a shrinking-field technique (median total dose, 63 Gy; range, 39.6-71 Gy), with 14 patients receiving interstitial brachytherapy as a component of treatment. Ten patients received adjuvant chemotherapy. Local control of disease was 82% at 5 years, and 95% after salvage therapy. The actuarial risk of distant disease recurrence was 27%, with an overall survival rate of 70% at 5 years. Histologic subtype, tumor grade, size of tumor, location of tumor, status of the surgical margins, use of chemotherapy, radiation dose, interval until initiation of radiation therapy, and use of a brachytherapy boost were analyzed to determine their effect on survival, local control, and freedom from distant metastasis. Microscopic involvement of the surgical margins predicted for local disease recurrence (P = 0.0002), distant disease recurrence (P = 0.008), and poorer overall survival (P = 0.02). Low histologic grade was favorably correlated with freedom from distant disease recurrence (P = 0.004) and survival (P = 0.002). Patients with liposarcomas had superior local control (P = 0.004) compared with patients with tumors of other histologic subtypes. Five patients experienced a complication of therapy, for an actuarial risk of 10% at 5 years. Only two patients required hospital admittance for treatment-related morbidity. These findings support the continued use of limb-preserving management for extremity sarcomas and emphasize the importance of the status of the surgical margins.