PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Hematopoietic: Platelet count greater than 80,000/mm3 Prothrombin time less than 15.0 seconds Hepatic: Bilirubin less than 2.0 mg/dL Renal: Not specified Other: Must be disease free for at least 5 years except for treated basal cell or squamous cell skin cancer