Dolastatin 10 in Treating Patients With Recurrent or Metastatic Soft Tissue Sarcoma

DISEASE CHARACTERISTICS: * Histologically proven recurrent or metastatic soft tissue sarcoma * No rhabdomyosarcoma, Ewing's sarcoma, chondrosarcoma, osteogenic sarcoma, mesothelioma, or Kaposi's sarcoma Bidimensionally measurable disease other than previously irradiated disease site(s) even if there has been progression within the radiation field * Pulmonary nodule(s) at least 1 x 1 cm No brain metastases PATIENT CHARACTERISTICS: * Age: 18 and over * Performance status: ECOG 0 or 1 * Absolute neutrophil count at least 2,000/mm3 * Platelet count at least 100,000/mm3 * Bilirubin no greater than 1.5 mg/dL * AST and ALT less than 1.5 times upper limit of normal (ULN) (3 times ULN if liver metastases present) * Creatinine no greater than 1.5 mg/dL * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 3 months after study * No uncontrolled infection * No history of prior malignancy within the past 5 years except basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or any other malignancy in complete remission PRIOR CONCURRENT THERAPY: * No more than 1 prior chemotherapy regimen in the adjuvant setting * No prior chemotherapy for metastatic disease * At least 4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosoureas) * At least 4 weeks since prior radiotherapy * Recovered from prior surgery