The human BRCA1 and BRCA2 genes are important genes on human chromosome 17 and 13, respectively, and the proteins they express play an important role in maintaining the stability of the human genome. However, mutations in BRCA1 and BRCA2 genes are highly correlated with familial hereditary breast cancer. Detection of BRCA1/2 mutations can screen for people at high risk of breast cancer, identify the presence of related mutations in the family, and assess the chance of breast cancer in susceptible people. The risk of breast cancer for women carrying the BRCA1 or BRCA2 gene ranges from 50-85%. However, each individual has differences in lifestyle habits and environment that may affect the incidence rate. This probability is only an approximate estimate, and having a genetic defect does not necessarily mean that you will get cancer. There is no need to overly panic if you test positive. You should consult with a specialist to enhance the frequency of screening and undergo relevant tests regularly. The BRCA1/2 gene test is suitable for: a. Multiple patients with breast cancer at a younger age (below 50 years old) in the family; b. Family history of breast or ovarian cancer; c. The same woman has breast and ovarian cancer successively or simultaneously; d. Both mammary glands have cancer; e. Male breast cancer patients in the family; f. Northern European Jewish descendants. Test method: The BRCA1/2 gene test generally requires only 5 ml of venous blood, extraction of genomic DNA, and bioinformatics analysis, and the test report can be issued in about one to two weeks. There are no special precautions to take before testing. Interventions for a positive BRCA1/2 test include: early, frequent, or intensive cancer screening; risk-reducing therapy (e.g., tamoxifen or raloxifene); and risk-reducing surgery (e.g., mastectomy or tubo-ovarian resection). Western women are more likely to develop hereditary breast cancer, carrying the breast cancer gene (BRCA1 or BRCA2) in 5-10%, so they have more prophylactic mastectomies. However, in our country, preventive mastectomy is not recommended, so that the interval between examinations can be shortened and timely surgery can be performed when signs of cancer are detected. In addition to genetic testing, breast ultrasound and mammogram are more effective means of detecting early breast cancer, and women aged 40-50 should go to a professional medical institution once every year to a year and a half for this kind of standardized breast examination and ultrasound, and the frequency of mammogram should follow the professional doctor’s advice; over 50 years old, it is recommended to do ultrasound and mammogram once a year; as the age increases such as over 70 years old, the frequency of examination will decrease; women aged 20-40 should also be examined every 2-3 years, but mammograms should be used sparingly or not at this age. If you belong to a high-risk group, you will need to shorten the interval between examinations.