PATIENT CHARACTERISTICS: Age: 65 and over OR Postmenopausal and ineligible/inappropriate for or declined other active node positive adjuvant studies Sex: Female Menopausal status: Postmenopausal, defined as: At least 1 year since last menstrual period Hysterectomized with bilateral oophorectomy Hysterectomized with 1 or both ovaries remaining and either: Over 60 FSH in postmenopausal range Not surgically castrated, under 60, and on HRT FSH elevated 2 weeks after HRT discontinued Performance status: Not specified Life expectancy: At least 7 years except for breast cancer Hematopoietic: WBC greater than 3,000/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 10 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL AST less than 2 times normal Renal: Creatinine no greater than 2.0 mg/dL BUN no greater than 25.0 mg/dL Other: No extensive macular degeneration on exam within 1 year of entry, e.g.: No exudative or atrophic macular lesions that reduce corrected vision to less than 20/40 Health adequate for protocol treatment No nutritional supplementation except single daily multivitamin No other vitamin A supplements Gynecologic exam within the past year required of women who retain a uterus No second malignancy within the past 10 years except: Inactive nonmelanomatous skin cancer Carcinoma in situ of the cervix Prior noninvasive contralateral breast cancer