What’s Up Doc?: Hereditary cancer and the importance of BRCA gene testing
By Medicine Hat News on September 5, 2017.
Longtime Newfoundland and Labrador politician, JudyFoote,has resigned as federal cabinet minister. Foote made the move to spend more time with her family after learning she has the BRCA gene, which is hereditary and can impact her children. BRCA stands for breast cancer. Foote said she has had two bouts with cancer, but as far as she knows, she is now cancer-free. That is good news. BRCA testing uses DNA analysis to identify harmful changes that signal a higher risk for breast and ovarian cancer. If a positive DNA mutation (changes in the structure of a gene) is discovered in one person, other family members can be tested to determine if they also carry a BRCA mutation. A genetic counsellor can make you understand your personal risks and prevention strategy. About one in 200 women in North America carry a BRCA1 or BRCA2 mutation. But among certain ethnic groups the prevalence is considerably higher. The frequency in those of Ashkenazi (Eastern European) Jewish ancestry is one in 50. Other groups with high frequencies of mutations include women from Iceland and Poland. Actor Angelina Jolie had a double mastectomy due to the presence of BRCA gene. Actor Pierce Brosnan’s daughter Charlotte Emily died of ovarian cancer at age 42. Brosnan is a former James Bond star whose first wife, Cassandra (Charlotte’s mother), also passed away due to the same disease in 1991 when she was 43. We know if you have a family history of ovarian cancer then the risk of ovarian cancer increases amongst women in that family. What is the difference between BRCA1 and BRCA2 genes? The types of cancers associated with the two genes are different. Carriers of BRCA1 gene mutation have a slightly increased risk of ovarian cancer compared to those with BRCA2. It is also known that carriers of BRCA2 genes have risks of different types of cancers, including pancreatic cancer and melanoma. For men with the BRCA2 mutation, there is an increased risk of both prostate and breast cancers. Who is eligible for BRCA genetic testing? A person who has a strong family history of cancer (the cancer must have occurred in young ages within the family) and a person who is a member of ethnic groups known to be affected. Based on your personal and family history a genetic counsellor can recommend BRCA genetic testing Early detection of breast cancer has dramatically changed the prognosis of the disease. We cannot say the same thing about ovarian cancer because we do not have any tests for early detection. More than 60 per cent of the women with ovarian cancer are in advanced stage when first diagnosed. Their five-year survival rate is less than 30 per cent. Their prognosis is poor and they have very few treatment options. To summarize, having a BRCA gene mutation is uncommon. Inherited BRCA gene mutations are responsible for about 5 to 10 per cent of breast cancers and about 15 per cent of ovarian cancers. If you have a personal or family history of breast or ovarian cancer then discuss your options with your doctor. Also understand the ethical, legal, and psychosocial implicationsof what you find. Check if the findings will affect your insurance policy. Dr. Bharwani is a general surgeon, freelance writer, photographer and author of A Doctor’s Journey and Doctor B’s Eight Steps to Wellness. His latest book is available at Shoppers Drug Mart and Coles Book Store (Medicine Hat Mall), Nutter’s (Dunmore Road),and http://www.nbharwani.com. You can discuss this article and other articles on his website: nbharwani.com and sign up for RSS feed, Twitter or get on the email list. 18-17
