RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using tamoxifen may fight breast cancer by blocking the uptake of estrogen. Combining chemotherapy with hormone therapy may kill more tumor cells. Chemoprevention therapy is the use of certain drugs to try to prevent the development or recurrence of cancer. The use of fenretinide may be an effective way to prevent the recurrence of breast cancer. It is not yet known whether tamoxifen plus fenretinide is more effective than tamoxifen alone for breast cancer.