DISEASE CHARACTERISTICS: Histologically proven previously treated stage 0, I, or II basal or squamous cell skin cancer

PATIENT CHARACTERISTICS: Age: 21 and over Performance status: ECOG 0-1 Life expectancy: Not specified Hematopoietic: WBC at least 3,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 11.0 g/dL Hepatic: Bilirubin no greater than 2 mg/dL SGOT less than 3 times normal Renal: Creatinine less than 2.0 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No significant clinical hearing loss or use of hearing aid No family history of early retinal blindness or ornithine diaminotransferase deficiency

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior bone marrow transplant No concurrent tamoxifen for cancer treatment or prophylaxis Chemotherapy:

Greater than 4 weeks since prior chemotherapy No concurrent cytotoxic chemotherapy Endocrine therapy: Greater than 4 weeks since prior hormonal therapy for cancer No concurrent prednisone No concurrent hormonal therapy for cancer treatment or prophylaxis Radiotherapy: Greater than 4 weeks since prior radiotherapy Surgery: Greater than 4 weeks since prior major surgery No prior solid organ transplant Other: At least 4 weeks since prior topical medications (e.g., tretinoin, isotretinoin, psoralen ultraviolet light therapy, or fluorouracil) for skin cancer No concurrent antiseizure medication