A Phase I Trial of Tamoxifen and 9-Cis-Retinoic Acid in Breast Cancer Patients

DISEASE CHARACTERISTICS: All patients must have histologically documented diagnosis of Stage III, or IV breast carcinoma. Patients with stage III that has completed chemotherapy: Estrogen receptor (ER) or progesterone receptor (PR) positive tumor required if premenopausal. Either ER/PR-positive or -negative tumor allowed if postmenopausal and have received prior chemotherapy. Patients may have stage IV with ER/PR-positive or -negative tumor. No CNS metastases, pseudotumor cereri, or seizures. PRIOR/CONCURRENT THERAPY: Patients who have ecovered from the toxic effects of prior therapy will be eligible. Patients with prior tamoxifen will be allowed to participate. At least 3 weeks must have elapsed since the last dose of chemotherapy. PATIENT CHARACTERISTICS: Age: 18 and over. Sex: Men and women. Menopausal status: Any status. Patients must have a performance status of ECOG 0-2. Patients must have Hematopoietic criteria of: ANC at least 1,500/mm(3). Platelet count at least 90,000/mm(3). Patients must have Hepatic criteria of: In the absence of tumor involvement: Bilirubin no greater than twice normal; SGOT no greater than twice normal; Alkaline phosphate no greater than twice normal; Fasting triglycerides less than 3 times normal. Patients must have Renal criteria of: Serum creatinine no greater than 1.5 mg/dL OR; Creatinine clearance at least 60 mL/min. Other: No allergy to study medications. No nonmalignant systemic disease that would preclude therapy. No second malignancy within 5 years except: Curatively treated basal cell skin carcinoma. Cervical carcinoma in situ. Pregnant women will be excluded. Negative pregnancy test required within 7 days prior to entry. Adequate contraception required for 4 weeks prior to, during, and for 1 year after study. Patients must give informed consent. Patients who are poor medical or psychiatric risks will be eligible.