Most inherited breast cancers are either BRCA1 (breast cancer gene one) or BRCA2 (breast cancer gene two). Everyone has these two genes. The functions of the genes are to repair cell damage and to keep the breast cells growing normally. The BRCA1 and BRCA2 genes are responsible for 10% of all breast cancer cases. If one is born with an abnormal BRCA1 or BRCA2 gene it does not necessarily mean they will have breast cancer. Scientists are finding new mutations on the genes called single nucleotide polymorphisms (SNP’s). These may cause a higher risk of breast cancer than people who don’t have the abnormal gene.
If one has an abnormal BRCA1 or BRCA2 gene and are diagnosed with breast cancer it is most likely because they have a family history of breast cancer, ovarian cancer, or other types of cancer. Family history can be a good way to tell if you’re at risk of a diagnosis. Breast cancer can also be quite a surprise though. You can be diagnosed even if you have the normal genes and there are no others in your family who suffered this disease.
You are more likely to have the abnormal BRCA1 or BRCA2 genes if you have blood relatives who were diagnosed with the cancer before the age of 50, there is breast and ovarian cancer within your family lineage (especially if one individual had both), there are other gland related cancers in the family, women in your family have had both breasts infected by the cancer, you are Ashkenazi Jewish (Eastern European)((, or if any males in your family have been diagnosed with breast cancer.
One out of eight women is diagnosed with breast cancer in their life time. It’s really common and can affect anyone unexpectedly. Survival rates of the cancer depend on the stage. The stages are O, I, IIA, IIB, IIIA, IIIB, IIIC, and IV. With the ones listed here the survival rate descended. It starts with a 93% survival rate and goes all the way down to a 15%. If you have an abnormal BRCA1 or BRCA2 gene there is an 80% chance of you being diagnosed with the cancer. Breast cancer is more common in young women.
Women with the abnormal genes also have a high chance of developing ovarian, colon, pancreatic, and thyroid cancers, as well as melanoma.
Men with the abnormal BRCA2 gene suffer a way higher chance of getting breast cancer than men who don’t. This usually develops around the age of 80. Men with the abnormal BRCA2 gene are seven times more likely to develop prostate cancer. The abnormal BRCA1 and BRCA2 genes also cause men to be more likely to develop other times of cancer too such as skin cancer.
There are other abnormal genes that can cause breast cancer. These genes are much rarer and have not been studied as much as the BRCA genes. These genes include ATM, p53, CHEK2, PTEN, and CDH1.The ATM gene is meant to help repair DNA and if it is abnormal its inability to repair the DNA can cause cancer. The p53 gene instructs the body to produce a protein that stops the growth of tumors. If this gene is abnormal the risk of breast cancer is higher-than-average. The CHEK2 also helps the body produce the tumor stopping protein. If the CHEK2 gene is abnormal Li-Fraumeni will be developed which can double the risk of breast cancer. The PTEN helps to regulate cell growth. If the PTEN gene is abnormal it can cause Cowden syndrome which is a rare disorder in which people have a higher risk of both benign (not cancer) and cancerous breast tumors, as well as growths in the digestive tract, thyroid, uterus, and ovaries.