The effect of surgery with radiation on pelvic Ewing sarcoma survival.

Background: Pelvic Ewing sarcoma (ES) has poorer outcomes than extremity-based lesions and the method of local control is controversial.

Methods: A retrospective review was performed of 40 primary pelvic or sacral ES treated by a single surgeon. All received modern chemotherapy and those that received radiation were treated with modern dosages.

Results: Fifty-five percent were disease-free at latest follow-up (median, 83.1 mos). Sixty-one percent had ≥ 99% necrosis, which was associated with 65% disease-free survival. Larger size (P = 0.016) and the absence of metastatic disease (P = 0.005) was predictive of survival. Eighty-three percent of relapsed patients were DOD. Half of patients who received surgery alone or RT alone have NED while 57% of those who received S/RT have NED. Complication rates were 69% (S/RT), 75% (surgery alone), 10% (RT alone). Functional outcomes were similar.

Conclusions: Primary pelvic ES is localized at presentation in 50% and the absence of metastases is the strongest predictor for survival. Chemotherapy is key, but excellent histologic response is neither a guarantee nor a necessity for survival. More than one-third die despite an excellent histologic response and at least one-third with lung metastases survive. With chemotherapy, radiation, and surgery, reasonable control of disease can be achieved. Methods: Case-control or retrospective cohort study.