Posters— Medical Oncology

EXTRASKELETAL, ADULT EWING FAMILY OF TUMORS (EFT): COMBINED TREATMENT IN 42 PATIENTS

Casali PG, Bertulli R, Santoro A, Lombardi F, Spreafico C, Dileo P, Gandola L, Navarria P, Gronchi A, Quagliuolo V, Valente M, Brega Massone P, Mastore M, Rolfo CD, Rasponi A, Cataldo I, Pilotti S, Azzarelli A (Istituto Nazionale Tumori, Milan, Italy; non-current address for SA, QV, MM, VM)

Background: Only small series of extraskeletal Ewing’s sarcoma or pPNET are available, after first report in 1975. Both skeletal and extraskeletal cases in adults are rare as well. Intervention: From 1988, over 10 years, 42 chemoradiotherapy-naive pts in the adult age (range = 16-58; median = 24 years), with diagnosis of extraskeletal Ewing’s sarcoma or pPNET, were prospectively treated with: primary chemotherapy (Ifosfamide + Epirubicin + Vincristine x 4-7); surgery, if feasible, in non-metastatic pts; radiotherapy + Cisplatin and Vincristine; consolidation chemotherapy (Ifosfamide + Dacarbazine + ActinomycinD, or Etoposide + Cisplatin or Ifosfamide, or high-dose Ifosfamide x 2-6).

Pt characteristics: Of 42 pts, 36 had only local disease: 31 had visible disease, 5 were NED at entry after diagnostic surgery; tumor originated from thorax (12), limbs (11), paravertebral region (7), pelvis (3), head & neck (3). All ED pts are evaluable for response to primary chemotherapy, save for one who received symptomatic concurrent chemo-radiotherapy. Six pts had evaluable metastatic disease (to lungs + liver + bone). Tumor size was >10 cm in 55% of isolated local lesions. Median follow-up for all pts is 86 mos.

Results: Response to chemotherapy was achieved in 72% of 36 evaluable pts. Among 30 pts with local disease, complete responses were 30% (6/9 were pathologically detected). The 10-year actuarial RFS was 46% in pts with local disease. Pts with limb and head & neck lesions had a RFS of 70%, versus 31% in pts with thoracic, paravertebral and pelvic disease. None of 6 pts with metastatic disease stayed disease-free.

Conclusions: 1) In this series of adult pts with extraskeletal EFT, long-term RFS was superimposible to childhood series of skeletal origin accrued in the same years, particularly if tumor size is considered. 2) The complete response rate seems lower. This might be relevant in mutuating treatments from protocols for skeletal disease. 3) A subgroup of pts with worse prognosis, due to origin from thorax, paravertebral region, and pelvis, was identified in this series. This is worth confirming. If so, these high-risk pts would need, and certainly metastatic pts do need other/new approaches.