Breast cancer occurs as a result of a combination of genetic and environmental factors. Although genetic factors played a role in the incidence of breast cancer, they were not the only determining factor.
1. Related genes
Breast cancer susceptibility genes (BRCA1 and BRCA2)
• BRCA1: In zone 12-21 of chromosome 17, which has a similar function to that of BRCA 2, which results in impairment of DNA restoration during mutation, as well as a function of chromosome arousals, which is transacting and disrupts normal cytological cycling points. The risk of breast cancer is 50-80 per cent for BRCA1 mutations and 24-40 per cent for ovarian cancer.
• BRCA2: DNA in zone 12-13, with long arms of chromosome number 13, capable of repairing the damage. When BRCA2 mutates, DNA restoration functions are reduced and minor damage to DNA changes significantly. The risk of breast cancer is 40-70 per cent for BRCA2 mutations and 11-18 per cent for ovarian cancer, while increasing the risk of other cancers, such as melanoma, oesophagus and stomach cancer.
Other genes: In addition to these two genes, other genes are also associated with the occurrence of breast cancer such as PALB2, PTEN, TP53 etc. The protein coded PALB2 has the effect of inhibiting the growth of tumours, which is a tumor inhibitor factor, and if the gene mutates, it is likely to lead to the formation of malignant tumours, with a significantly higher risk of breast cancer among the population carrying it. The PTEN gene regulates the synthesis of a particular protein, which is present in almost all tissues. This protein, as a tumor inhibitor factor, regulates the cycle of cell fragmentation by preventing cell growth, rapid break-ups or uncontrolled break-ups. The TP53 gene, also known as the p53 gene, is an important anti-cancer gene whose coding protein p53 regulates cell fragmentation.
Genetic probabilities
The genetic probability of breast cancer is around 10 per cent, i.e. about 10 per cent of the population with breast cancer is genetic.
• The incidence of breast cancer among first-degree relatives (e.g. parents, children and siblings) increases by about two times the incidence of intergenerational cancer; in the case of two or more immediate family members, the incidence of breast cancer among relatives increases by about 10 times; and in the case of younger women, the genetic tendency is more pronounced.
3. Impact factors
Age: The incidence of breast cancer increases with age, and the older the risk of breast cancer increases.
Lifestyle: Unhealthful lifestyles can also increase the risk of breast cancer, such as chronic alcohol consumption, smoking, lack of exercise, high-fat diet, etc.
Breast disease history: Breast cancer can increase the risk of breast cancer if there is an increase in breast growth, mammoma, mammography within the catheter.
Ionizing radiation: Long-term exposure to ionizing radiation, such as X-rays, may increase the risk of breast cancer.
• Hormonal factors: chronic administration of estrogens, early menstruation, late menopause, infertility and late first childbirth, and short breastfeeding periods can increase or prolong exposure to estrogens in the body and increase the risk of breast cancer.
In general, even if there is a genetic risk of breast cancer in the family, the risk of disease can be reduced by means of lifestyle changes and regular breast screening. If there is a family history of breast cancer, it is recommended that breast screening be conducted on a regular basis to maintain a healthy lifestyle to reduce the risk of breast cancer. At the same time, the patient is advised to undergo regular self-examination, i.e., self-censorship to find out if there are pockets in the breast, and if so, to have access to medical care in a timely manner.
