Megace (generic name, megestrol acetate) is one of a class of drugs called anti-estrogens.
Megace works by blocking the growth-stimulating effects of estrogen on cancer cells containing receptors for estrogen. When estrogen-dependent breast cancer cells are "starved," their multiplication is inhibited.
Another benefit of Megace is that it can enhance the appetite of cancer patients who have lost appetite and weight.
1. National Cancer Institute. NCI Drug Dictionary. Accessed at www.cancer.gov/drugdictionary/.