Marimastat or No Further Therapy in Treating Women With Metastatic Breast Cancer That Is Responding or Stable Following Chemotherapy

DISEASE CHARACTERISTICS: Histologically confirmed adenocarcinoma of the breast with previous manifestations of progressing regional or metastatic cancer Received one prior systemic chemotherapy regimen for the treatment of metastases, which meets all of the following criteria: Included either doxorubicin, a taxane (i.e., paclitaxel or docetaxel), or both 6-8 courses were given If weekly taxane therapy received, at least 12 doses were given Recovered from all related toxic effects (except alopecia and/or neuropathy) 3-6 weeks have elapsed since last course of chemotherapy was given No more than 40 weeks have elapsed since the first dose of chemotherapy for metastases No current or prior history of brain metastases Responding or stable disease since the initiation of systemic chemotherapy (i.e., no disease progression) required No prior enrollment on ECOG trials for metastatic disease PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal Status: Not specified Performance status: ECOG 0 or 1 Hematopoietic: Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT no greater 2 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL Other: Not pregnant or nursing Negative pregnancy test required if pre- or peri-menopausal (i.e., last menstrual period within one year prior to study) Pre- or peri-menopausal sexually active women must use effective contraception No other invasive malignancy w…