It is estimated that 5% to 10% of breast cancers are hereditary, caused by abnormal genes passed from parent to child. Genes are particles in cells, contained in chromosomes and made from DNA (deoxyribonucleic acid). DNA contains instructions for making proteins. And proteins control the structure and function of all the cells that make up your body.
Abnormalities in DNA are like typographical errors that lead to erroneous cell growth or function. In any person, if there is a mutation in a gene, the same error will appear in all cells that contain the same gene. It is like a manual, in which all copies have the same typographical error.
Most inherited breast cancers are associated with two abnormal genes: BRCA1 (BReast CAncer one gene) and BRCA2 (BReast CAncer two gene) ... Everyone has the BRCA1 and BRCA2 genes. The function of the BRCA genes is to repair cell damage and keep the mammary glands, ovaries, and other cells functioning normally. But when these genes contain abnormalities or mutations that are passed down from generation to generation, the genes do not function normally and there is a high risk of developing breast cancer, ovarian cancer and other cancers. Abnormal BRCA1 and BRCA2 genes account for about 10% of all breast cancers, or 1 in every 10 cases.
Having an abnormal BRCA1 or BRCA2 gene does not mean you will be diagnosed with breast cancer. Researchers have already shown that other mutations in chromosome elements - SNPs (single nucleotide polymorphisms) - may be associated with a higher risk of breast cancer in women with an abnormal BRCA1 gene, as well as in women who have not inherited the abnormal breast cancer gene. p>
Women who are diagnosed with breast cancer and have an abnormal BRCA1 or BRCA2 gene often have a family history of breast cancer, ovarian cancer, and other cancers. However, most people who develop breast cancer do not inherit the abnormal breast cancer gene and do not have a family history of the disease.
People are significantly more likely to develop breast cancer if:
There are blood relatives (grandmothers, mothers, sisters, aunts) on the mother's or father's side who had breast cancer diagnosed before age 50.
family members have breast or ovarian cancer.
A relative with triple negative breast cancer.
In addition to breast cancer, family members have other cancers such as prostate cancer , melanoma, pancreatic cancer, cancer of the stomach, uterus, thyroid gland, colon cancer and / or sarcoma.
The women in the family had cancer in both breasts.
If one a family member has an abnormal gene for breast cancer, this does not mean that all family members will. Women who have an abnormal BRCA1 or BRCA2 gene (or both)may have up to an 80% risk of being diagnosed with breast cancer in their lifetime. Breast cancer associated with an abnormal BRCA1 or BRCA2 gene tends to develop in young women and is more common in both breasts than cancer in women without these abnormal genes.
Women with an abnormal BRCA1 or BRCA2 gene also have an increased risk of ovarian, colon and pancreatic cancers and melanoma. Men with the abnormal BRCA2 gene have a higher risk of breast cancer than men who do not - about 8% by the time they turn 80. This is about 80 times the average.
Men with an abnormal BRCA1 gene have a slightly higher risk of developing prostate cancer. Men with the abnormal BRCA2 gene are 7 times more likely to have prostate cancer than men without the abnormal gene. The risk of developing skin or digestive tract cancer may also be slightly higher in men with abnormal BRCA1 or BRCA2 genes.
A good example of the hereditary nature of breast cancer is the case of the famous actress Angelina Jolie, whose mother and grandmother died of cancer breasts. Angelina Jolie performed a preventive operation to remove the breast and its reconstruction ... Sometimes in similar clinical cases, doctors may recommend removing the ovaries in order to prevent cancer. Preventive surgery eliminates the risk of breast cancer
There is a concept of the absolute cumulative risk of cancer and the relative risk. The absolute cumulative risk of breast cancer according to 2013 data in the Russian Federation is 5.3%. This means that in the modern population, the probability of developing breast cancer is 5.3% (within 75 years of life).
Having a first-order blood relative, which includes the mother as a whole, increases the risk of breast cancer by about 3 times is the relative risk ratio.
However, the relative risk may be higher if there are identified BRCA gene mutations or confirmed genetic syndromes associated with an increased risk of breast cancer.
Thus, the risk a daughter whose mother had breast cancer can be estimated at about 16% chance of developing breast cancer within 75 years of life. And even higher if the daughter lives longer.
It should also be noted that the daughter will also have an increased risk of ovarian cancer (although not as much as breast cancer).
Hence Conclusion: such a daughter needs to be observed annually by an oncologist from the age of 35 and regularly perform X-ray mammography. Perhaps it makes sense to do an analysis of the BRCA genes for mutations after oncogenetic counseling.
And I would recommend taking insurance against cancer so that you will be fully armed if it does come. There are plenty of good suggestions on this topic right now.