O6-benzylguanine and Carmustine in Treating Patients With Unresectable Locally Recurrent or Metastatic Melanoma

DISEASE CHARACTERISTICS: Histologically proven unresectable locally recurrent or metastatic melanoma Chemotherapy naive with no more than 2 prior immunotherapy regimens (including cytokines, vaccines, or adjuvant interferon) OR Prior chemotherapy failure with no more than 2 prior immunotherapy regimens (including adjuvant interferon) and no more than 1 prior chemotherapy regimen (which may include carmustine) not including antiangiogenesis therapy Measurable disease At least 20 mm in at least 1 dimension by conventional technique OR at least 10 mm in at least 1 dimension by spiral CT scan No disease confined only to the CNS No uncontrolled symptomatic brain metastases regardless of other disease sites PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: WBC at least 3,000/mm^3 Absolute neutrophil count at least 1,200/mm^3 Platelet count at least 100,000/mm^3 Hepatic: Bilirubin no greater than 1.5 mg/dL AST and/or ALT no greater than 3 times upper limit of normal PT normal Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 60 mL/min Pulmonary: DLCO at least 70% predicted Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No concurrent significant psychiatric or medical illness, including active infections, that would interfere with study therapy or increase risk No other malignancy within the past 5 years except curatively treated nonmelanomatous skin cancer, carcinoma in situ of the cervix, or superficial bladder cancer PRIOR CONCURRENT THERAPY: Chemotherapy: At least 4 weeks since prior systemic chemotherapy (at least 6 weeks since prior carmustine or mitomycin) and recovered No other concurrent chemotherapy or investigational antineoplastic drugs Radiotherapy: At least 2 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: At least 3 weeks since prior major surgery and recovered Other: At least 4 weeks since other prior anticancer systemic therapy and recovered