Extracranial primitive neuroectodermal tumors. The memorial sloan‐kettering cancer center experience

Abstract

The clinical data of 54 patients (57% males) with extracranial primitive neuroectodermal tumors (PNET) seen over a 20‐year period at Memorial Sloan‐Kettering Cancer Center were reviewed. The age at diagnosis ranged from 1 month to 81 years (median, 17 years). One PNET arose in a previously irradiated site. One patient had an unaffected identical twin. Primary sites were thoracopulmonary (n = 25), pelvis (n = 12), retroperitoneum or abdomen (n = 10), limbs (n = 5), neck (n = 1), and unknown (n = 1). At diagnosis, epidural extension was present in 13 patients with truncal primaries, and 11 patients had distant metastases. All of the latter died with disease. Progression‐free survival (PFS) among the 43 patients with localized tumors (all >5 cm) was 25% at 24 months. Two of 13 patients who relapsed after more than 12 months without therapy were long‐term survivors. Patients with localized PNET who had resection of all gross disease within 3 months of diagnosis had a significantly longer PFS (P = 0.0003). Radiation therapy caused tumor shrinkage but was not curative of measurable disease. A doseresponse effect was evident with the most commonly used drug, cyclophosphamide. Myeloablative regimens using melphalan (n = 8) or thiotepa (n = 1) with autologous bone marrow rescue were not clearly beneficial. The treatment results favor: (1) early surgical removal, (2) dose‐intensive use of drugs active against PNET (especially cyclophosphamide), and (3) radiation therapy to ablate residual microscopic disease. Copyright © 1991 American Cancer Society