JAMA: Drug prevention of breast cancer, what factors to weigh, four drugs how to choose?

Breast cancer is a common high incidence of cancer in women and one of the leading causes of death from malignant tumors in women. !----breast cancer screening is an important means of early detection of the disease, but it does not slow the progression of the disease, but there are several drugs can effectively reduce the risk of breast cancer.however, the current rate of primary prevention of breast cancer is not high. in two recent articles published in the Journal of the American Medical Association (JAMA),, experts from the University of California, San Francisco (UCSF) and UCLA reviewed the available evidence from different perspectives and described the benefits and risks of preventive drug use to promote the rational clinical use of these drugs.which populations need medication to prevent breast cancer first, an important principle is to ensure that the benefits of primary prevention of drug use outweigh harm.therefore, we need to identify the right people., women over the age of 35 who have an increased risk of breast cancer may consider preventive medication.But the extent of the "increased risk" is not clearly defined, with most studies and the USPSTF recommendations defining a 3% chance of developing breast cancer over the next five years., risk assessments often take into account age, primary age, pregnancy history, previous mammograms, and family history and genetic risks such as BRCA gene mutations.in the general U.S. population, proven risk models include the Breast Cancer Risk Assessment Tool, the Breast Cancer Surveillance Consortium Risk Calculator, and the Breast Cancer Intervention Research Risk Assessment Tool.a 2019 study at the Large Breast Target Center found that the first two tools were more accurate, with more consistent risk in the population with the actual observed risk;the pros and cons of the four preventive drugs currently, there are two main types of drugs used to reduce the risk of breast cancer: (1) selective estrogen receptor regulators (SERM), including tamoxifen and reloxifen;typical preventive drug use period is 5 years.is currently only tamoxifen approved by the U.S. FDA for breast cancer prevention in premenopausal women, and other drug indications are postmenopausal drugs.the evidence for the effectiveness of selective estrogen receptor regulators is strongest.meta-analysis showed that for every 1,000 women who took a five-year selective estrogen receptor regulator, the incidence of invasive breast cancer was reduced by 7-9 cases.randomized trials showed that taking tamoxifen for five years reduced the risk of breast cancer for 20 years. randomized trials, there was no difference in the prevention effect of reloxifen and his moxifen for 6 years, after 9.7 years, the reloxifen group had slightly worse prevention effect, the risk of invasive breast cancer was 19%, but taking into account serious adverse events, the overall mortality rate was reduced by 13%. other benefits of such drugs, which increase bone density, are associated with a reduced risk of fractures in postmenopausal women. both reloxifen and his moxifen increase the risk of venous thromboembolism in terms of side effects. compared to tamoxifen, the risk of venous thromboembolism in people who took reloxifen was 25 percent lower, and the absolute risk was equivalent to five years of preventive medication for every 1009 women, reducing the number of vein thrombosis cases by 4 cases. in addition, tamoxifen is associated with an increased risk of uterine cancer (5 more cases per 1,000 women in five years). two selective estrogen receptor regulators can cause hot flashes, tamoxifen can also cause more adverse gynecological reactions, including menstrual abnormalities, sexual dysfunction and white ribbons. Despite the relatively poor experimental data, the preventive effects of aromatase inhibitors have received more attention and been written in guidelines in recent years. USPSTF reviewed evidence that 16 cases of breast cancer were reduced for every 1,000 women who took five years of aromatase inhibitors. The latest long-term data on anacurin, officially published in The Lancet at the end of 2019, show that women who took anacurin had a 49 percent lower risk of breast cancer during the 12 years of preventive use (i.e. 7 years after discontinuing the drug). Professor Jack Cuzick, co-chair of the Research, Queen Mary University of London, points out that "anacurinis is better than tamoxifen (a 28 per cent lower risk)." the main adverse reactions to " aromatase inhibitors are joint pain, myopathy, and bone density reduction, which can also cause hot flashes (but are usually less severe than those caused by selective estrogen receptor regulators). the trade-offs and precautions for actual medication, two JAMA articles point out that patients and doctors should make a decision on preventive medication sourcing them together according to their individual circumstances. potential benefits of starting the drug earlier in terms of treatment timing include: selective estrogen receptor regulators have been shown to reduce breast cancer risk for at least 15-20 years, early to benefit from early prevention, and the risk of venous thromboembolism and uterine cancer increases with age, reducing side effects by receiving selective estrogen receptor regulators at a younger age. in specific drug options, usually tamoxifen or reloxifen is a first-line treatment option. but taking into account the benefits and side effects of different drugs, some special cases of medication reference as follows: for postmenopausal women who still have a uterus, reloxifen may be a more appropriate option because it does not increase the risk of uterine cancer. however, hemothine has stronger evidence of long-term benefits and may be more suitable for women who have had their uterus removed. for postmenopausal women with a higher risk of thromboembolism, aromatase inhibitors may be more suitable for postmenopausal women with low risk of osteoporosis. , it is important to note that in many breast cancer subtypes, these drugs do not reduce the risk of estrogen receptor-negative breast cancer. , even if it is preventive, women taking the drug should continue to be screened for breast cancer by referring to the guidelines. future direction sourcing the future of breast cancer prevention drugs, dr. Iwey Shieh and Dr. Jeffrey A. Tice of UCSF Generaleand, point out three points in the JAMA article: Integrating breast cancer risk models into electronic medical records can help automate risk assessment and help identify high-risk women who are suitable for preventive use. genetic testing data can help improve the performance of risk prediction and better support clinical decision-making. in addition, some indicators, such as breast density, may help identify women who do not respond to treatment, which should stop treatment. of course, the evidence for these drugs is constantly accumulating, and there may be innovative preventive drugs in the future. expects a growing range of drug options and growing evidence to help more high-risk women stay away from breast cancer. .