PATIENT CHARACTERISTICS: Age: 16 and over Performance status: ECOG 0-2 Life expectancy: At least 12 weeks Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: Not pregnant or nursing Effective contraception use by men or women of reproductive potential No prior malignancies within 5 years except: Adequately treated nonmelanomatous skin cancer Adequately treated carcinoma in situ of the cervix No other concurrent malignancies No prior diagnosis of breast cancer, melanoma, or hypernephroma No major medical illness that would preclude prolonged administration of marimastat or required follow up No active peptic ulceration or symptoms suggestive of this diagnosis No grade 3 or 4 musculoskeletal disorders