Genetic testing for breast and ovarian cancer – should all women be tested?

Yesterday in the UK, a team from Barts Cancer Institute, Queen Mary University in London reported that it may be more cost effective and help prevent cancer in women if we screen the entire population over 30 years of age for the high risk genes, BRCA1 and BRCA2.  BRCA stands for BReast CAncer.

Breast cancer is caused when breast tissue divides abnormally and causes a lump. Over 80% of lumps in the breast are not cancer, but for the 20% that are, there are a range of treatments that can be offered to stop the cancer spreading.

Breast cancer has increased because of life style changes, such as an increase in drinking alcohol and smoking.  The lifetime risk of getting breast cancer is 1 in 8 which means about 13% of women will get breast cancer.  The majority (80%) of breast cancer occurs in women over 50.

Breast cancer globally accounts for nearly 1.7 million cancer cases.  About 5-10% of breast cancer is caused by mutations (errors in the gene) in BRCA1 and BRCA2 genes.  Women with an abnormal BRCA1 gene have a worse prognosis than women with an abnormal BRCA2 genes, 5 years after diagnosis.

BRCA1 regulates how the cells in the breast grow, making sure they do not grow and divide too rapidly or in an uncontrolled way. The gene makes a protein which repairs damaged DNA. When the gene is mutated, the protein become defective and so it cannot repair damaged DNA which results in abnormal growth of the breast tissue. Mutations in BRCA1 also increase the risk of ovarian, prostate and colon cancer. There are over 600 different mutations that can occur in the gene, but not all lead to cancer.

BRCA2 has a similar function to BRCA1.

But if you have the mutated gene, it does not mean you will definitely get cancer.  Over their lifetime, carriers have a 69-72% chance of developing breast cancer and a 17-44% chance of developing ovarian cancer.  If your gene is not faulty, the risk of breast cancer drops to 12% and ovarian cancer to  2%.

Since only 5-10% of breast cancer is caused by BRCA1 and BRCA2, currently genetic testing is only offered to those who have a family history.  But the new study from Barts suggests that 64,000 fewer breast cancers and17,000 fewer ovarian cancers could be prevented if all women over 30 were tested.

Dr Ranjit Manchanda, Consultant Gynaecological Oncologist, Barts Cancer Institute said “Our findings support the concept of broadening genetic testing for breast and ovarian cancer genes across the entire population, beyond just the current criteria-based approach.”“With the costs of testing falling, this approach can ensure that more women can take preventative action to reduce their risk or undertake regular screening.”

Would you like to know if you carried the BRCA1 or BRCA2 mutation?

Read More:

Global women – http://www.globalwomenconnected.com/2017/04/one-five-breast-cancer-patients-benefit-existing-treatment/

Global women – http://www.globalwomenconnected.com/2017/02/exercise-weight-management-important-lifestyle-changes-reducing-breast-cancer-recurrence/

Global women – http://www.globalwomenconnected.com/2017/01/women-friends-higher-breast-cancer-survival/