PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: WHO 0-2 Life expectancy: Greater than 3 months Hematopoietic: Hemoglobin at least 9 g/dL WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 1.2 mg/dL ALT less than 2 times upper limit of normal (ULN) Alkaline phosphatase less than 2 times ULN Renal: Creatinine less than 1.5 mg/dL Other: Fertile patients must use effective contraception No concurrent malignancy except cone biopsied carcinoma in situ of the cervix and adequately treated basal or squamous cell carcinoma of the skin No other serious medical condition No uncontrolled infection or serious infection within the past 28 days Must live within 1 hour of Mount Vernon Hospital, UK