DISEASE CHARACTERISTICS: Documented relapsed or refractory germ cell cancer of the following sites of origin: Testes Ovary Retroperitoneum Mediastinum Other sites Any stage of disease allowed Any histologic subtype allowed Seminoma only allowed if ineligible for radiotherapy Failed to achieve complete remission (CR) following at least 3 courses of a standard platinum-containing regimen or experienced clear relapse following CR obtained with such a regimen Absence of tumor markers in the presence of stable residual masses after initial treatment may be allowed (surgical biopsy should be performed; if medically safe, to confirm persistence of disease and rule out mature teratoma or fibrosis) Prior CNS involvement allowed in the absence of gross residual CNS tumor following definitive local therapy (surgery plus radiotherapy) No gross tumor involvement on bone marrow biopsy