Primary Ewing's sarcoma of the ribs. A report from the intergroup Ewing's sarcoma study

Thirty-six patients with primary Ewing's sarcoma of the ribs have been reviewed. Of these, 21 had clinically localized disease at diagnosis and were entered on protocol IESS 7299, eight had regional and seven metastatic disease at diagnosis and were entered on protocol 7450. The 21 with localized disease were treated with surgical excision or biopsy, followed by local radiotherapy (in all but one patient) and randomization to one of three chemotherapy regimens. Eleven patients (52%) remain disease-free for periods ranging from 18 to 64 months, respectively. Seven of eight patients who underwent complete surgical excision of the primary lesion remain disease-free, compared with four of 12 (excluding one patient who died disease-free) who remain disease-free after partial excision or biopsy. However, analysis of size of tumor at diagnosis reveals that smaller primary tumors have a better prognosis irrespective of extent of surgery. Protocol IESS 7450, consisted of radiotherapy to all areas of known disease and four drug chemotherapy. Four (50%) with regional disease but none with metastatic disease have remained alive and continuously disease-free. It is concluded that an aggressive approach to Ewing's sarcoma of the ribs is justified by the results, as even regional disease may be curable. The apparent prognostic advantage for those patients undergoing surgical excision may be explained by patient selection.