Combined Preoperative Hypofractionated Radiotherapy With Doxorubicin-Ifosfamide Chemotherapy in Marginally Resectable Soft Tissue Sarcomas: Results of a Phase 2 Clinical Trial.

ABSTRACT

PURPOSE: There is no standard treatment for marginally resectable soft tissue sarcomas (STSs) of the extremities and trunk wall, and current approaches produce unsatisfactory results. We hypothesized that the combination of doxorubicin-ifosfamide (AI) chemotherapy and 5 × 5 Gy hypofractionated radiotherapy can generate a higher ratio of limb-sparing or conservative surgeries with negative microscopic margins (R0) and acceptable treatment toxicity. METHODS AND MATERIALS We conducted a single-arm prospective clinical trial. Treatment combined 1 cycle of AI with subsequent 5 × 5 Gy radiotherapy within 1 week, followed by 2 cycles of AI and surgery. The primary endpoint was to assess the number of patients in whom en bloc R0 resection was achieved. RESULTS: Forty-six patients met the eligibility criteria. Three patients had resectable lung metastases at baseline. Forty-two received the planned protocol treatment. In 2 patients, the treatment was prematurely stopped because of the toxicity of chemotherapy. One patient died of septic shock because of severe bone marrow suppression after the second AI cycle; a second death was not related to treatment for STS. Three patients underwent amputation. In 72% of patients in the intention-to-treat analysis, we achieved en bloc R0 resections. Grade 3+ Common Terminology Criteria for Adverse Events 4.03 chemotherapy toxicity requiring dose reduction or treatment interruption occurred in 15 patients. Wound complications occurred in 18 patients, but they were severe in only 6 patients. CONCLUSIONS: Preoperative AI combined with 5 × 5 Gy radiotherapy is a promising method for the management of marginally resectable STS. This protocol enables a high ratio of R0 limb-sparing or conservative surgeries. Further evaluation of this strategy is warranted.