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Hydroxychloroquine, Palbociclib, and Letrozole before Surgery in Treating Patients with Estrogen Receptor Positive, HER2 Negative Breast Cancer

Trial Status: administratively complete

This phase I/II trial studies the side effects and best dose of hydroxychloroquine when given together with palbociclib and letrozole before surgery in treating patients with estrogen receptor positive, HER2 negative breast cancer. Hydroxychloroquine is a substance that decreases immune responses in the body. Palbociclib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Estrogen can cause the growth of breast cancer cells. Drugs, such as letrozole, may lessen the amount of estrogen made by the body. Giving hydroxychloroquine, palbociclib, and letrozole before surgery may work better than palbociclib and letrozole in treating patients with breast cancer.