What are the Effects of Tamoxifen on Breast Cancer?

Tamoxifen is a drug that is often prescribed to treat breast cancer that is considered hormone receptor positive. The usual effect of tamoxifen on breast cancer is to shrink tumors just before surgery, and prevent the cancer from growing or spreading to the rest of the body. It can also reduce the chances of breast cancer developing in women who have an increased risk of it. It works by preventing estrogen from attaching to the hormone receptors that cancer cells have. It can be used either before or after surgery, and may be used at the same time as other treatments, such as radiation therapy.

This drug is usually the best choice for women who have not gone through menopause yet, though women who are postmenopausal can also take it. One of the main effects of tamoxifen on breast cancer is to reduce the size of tumors so that they are easier to remove through surgery. Doctors may also prescribe this drug in the hopes of reducing the chances of the cancer returning, lower the risk of it spreading to the other breast or additional body parts, or slow its growth overall. It can even be used as a preventive measure, as some doctors prescribe this drug to women who have a high risk of developing breast cancer, but have not yet been diagnosed with it. Additionally, it may keep cholesterol levels low, and reduce the progression of postmenopausal bone loss.

While using tamoxifen on breast cancer is usually effective, there are some side effects. One of the main downsides is that it can increase the chances of endometrial cancer, which affects the uterine lining. It can also result in blood clots, stroke, or bone pain. Symptoms of menopause may also appear, including mood swings, hot flashes, night sweats, vaginal dryness, nausea, thinning hair, and low libido. In addition to these symptoms, this drug can also cause premenopausal women to start menopause before they would on their own.

Most doctors recommend that this drug be taken once per day at the same time to have the highest chances of seeing the most beneficial effects of tamoxifen on breast cancer. It is typical to take it for five years, but some women may take it for up to three years and then begin taking an aromatase inhibitor instead, which is a breast cancer treatment that is considered best for postmenopausal women. It should be noted that the effects of tamoxifen on breast cancer are usually the same in men with this type of cancer as they are in women.