The World Health Organization (WHO) believes that more than 40% of cancers can be prevented. With the increasing incidence of breast cancer, more and more people are concerned about the prevention of breast cancer. Eating those things can prevent breast cancer and what drugs can prevent breast cancer have become the most frequently asked questions by internet users. This article will not elaborate too much on the issue of eating. Today’s topic is “Are there drugs that can prevent breast cancer?”
Chemoprevention is mainly aimed at pre- and postmenopausal women who are at high risk of breast cancer. Tamoxifen is recommended for premenopausal women, tamoxifen and raloxifene, anastrozole, and exemestane for postmenopausal women. They are effective options for the prevention of ER-positive breast cancer and are currently considered ineffective for the prevention of ER-negative breast cancer. Exemestane and anastrozole are not currently approved by the FDA for breast cancer risk reduction.
Tamoxifen is a nonsteroidal drug that acts in the body primarily by antagonizing estrogen. It is likely that tamoxifen inhibits the action of endogenous estrogen through estrogen receptor binding and competes with ER to bind and form a receptor complex that blocks the action of estrogen, thereby inhibiting the proliferation of breast cancer cells. For breast cancer risk reduction, the tamoxifen dose should be 20 mg/d. This dose was derived from a large randomized breast cancer risk reduction trial, and the safety and efficacy of the substitutable dose and duration of administration have not been evaluated.
No studies have evaluated the optimal age for initiation of tamoxifen to reduce the risk of breast cancer and the maximum net benefit for premenopausal women at high risk. To reduce the risk of breast cancer, tamoxifen is typically applied for five years. When you stop taking the drug, the benefit of risk reduction lasts for 10 years.
Who can take tamoxifen to reduce the risk of breast cancer?
1. Pre- and post-menopausal women older than 35 years of age with a 5-year risk of breast cancer in the gail model is higher than 1.67%
2.Patients with lobular carcinoma in situ
3.Atypical hyperplasia of the breast
4, two and more first-degree relatives with breast cancer
Side effects of tamoxifen: hot flashes, night sweats, vaginal bleeding, vaginal dryness, and increased incidence of thrombosis-related events and endometrial cancer with tamoxifen.
Therefore, tamoxifen is not suitable for the following people to reduce the risk of breast cancer
1. History of deep vein thrombosis
2.History of pulmonary embolism
3.History of stroke
4.History of transient ischemic heart disease
5.Atherosclerosis
6.Patients who are bedridden for a long time
7.High risk group of endometrial cancer
Women who are taking estrogen, progestin, androgen and contraceptive pills should stop taking the above drugs before starting tamoxifen treatment. Women who are pregnant or planning to get pregnant should discontinue tamoxifen.
Oral raloxifene 60 mg/d for 5 years is a viable alternative option for reducing the risk of breast cancer in postmenopausal women at high risk. It is also associated with a significantly lower risk of benign and malignant uterine disease and thrombotic events than tamoxifen. Raloxifene is not available for use in premenopausal women.
However, in China, tamoxifen, raloxifene, exemestane and anastrozole are approved for indications that do not “reduce the risk of breast cancer”. Therefore, it is important to talk to your doctor first about the benefits and risks of chemoprevention of breast cancer, rather than taking them on your own.