Metastatic Ewing sarcoma/PNET of bone at diagnosis: Prognostic factors - Areport from Saudi Arabia

Background. To evaluate outcome and prognostic factors in Saudi Arabian pat ients with metastatic Ewing sarcoma and PNET of bone (PMES) at diagnosis. P rocedure. Ninety-nine of 304 (33%) consecutive patients with Ewing sarcoma and PNET of bone registered at our centre from 1975 to 1998, had metastatic disease at registration and 93 were available for analysis. The maximum x- axis diameter of the primary tumor was used as the measure of primary tumor size. Usually a trial of systemic treatment was undertaken before a decisi on was made on local treatment. Standard chemotherapy regimens were used in all treated patients. Forty-one (44%) patients did not receive radical loc al treatment due to an inadequate response to chemotherapy, or a decision n ot to undertake more than palliative treatment. Radical treatment of the pr imary site was radiation alone 41 (79%), resection alone 7 (13%), and resec tion and radiation 4 (8%). Results. The 5-year survival rates were 9% for a ll 93 evaluable patients, 16% for 52 patients who received chemotherapy and radical local treatment, 0% for 41 patients who received lesser treatment, 19% for 43 patients with lung metastases alone, and 0% (P=0.002) for 50 pa tients with other sites involved. For 60 patients with imaging data, 5-year survivals were 34 and 0% when the maximum transverse diameter of the prima ry tumor was <10 cm (N=20) and <greater than or equal to>10 cm (N=40), resp ectively. Conclusions. Small primary tumor size and the presence of lung me tastases alone were the only significant favorable prognostic factors. Earl ier diagnosis will be the basis for better results. Med Pediatr Oncol 2001; 37:383-389. (C) 2001 Wiley-Liss, Inc.