Letrozole for breast cancer is a medicine often used to treat breast cancer. It belongs to a class of medications known as aromatase inhibitors, which act by lowering estrogen production in the body. Estrogen can drive the growth of certain types of breast cancer, therefore by reducing estrogen levels, Letrozole can help reduce or stop cancer cell proliferation. For many women who have been diagnosed with breast cancer, Letrozole can be an important element of their treatment. It is frequently taken following surgery or different treatments to help prevent the cancer from recurring. While Letrozole can cause side effects such as hot flashes, joint discomfort, and exhaustion, many women find that the benefits exceed the risks.