Sunday, April 20, 2014

BRCA Mutations and Male Breast Cancer

Various websites, like MedicineNet, report that 99% of all breast cancers are found in females.  I then thought about the other 1% of males that acquire breast cancer.  I wanted to learn more about the causation of male breast cancer and possible trends among possible gene mutations.  I narrowed my search down to mutations among both the BRCA 1 and BRCA 2 genes.  Although this is not the subject of mine and Ellie Pringle's cancer project, I thought it would be interesting enough to explore deeper.  

I first wanted to learn the function of the BRCA1/2 gene.  According to the National Cancer Institute, BRCA are human genes that produce tumor suppressor proteins.  As we learned in class, tumor suppressor proteins play a large role in ensuring stability in the cells genetic material.  This gene is important for DNA damage recognition, double strand break repair, checkpoint control, transcription regulation and chromatin remodeling.  BRCA 1/2 carriers can obtain the mutation from either parent.  It affects the risks of cancer in both men and women. 

The figure below helps to explain the function of the product protein from BRCA 1/2 genes and other repair proteins in the cell.  

It makes sense why more time and money is spent on learning more about BRCA mutations in women rather than men.  These mutations account for 5-10% of all breast cancers in women and 20-25% of all hereditary breast cancers.  A journal titled "Cancer Risks for Male Carriers of Germline Mutations in BRCA1 and BRCA2" published in 2004 estimates the risk associated with males carrying BRCA mutations.  It suggests that attention needs to be focused on males with BRCA mutations.  They contribute to breast, prostate and pancreatic cancers among males.  The lifetime risk of males with BRCA2 mutations is 80-100% higher than the rest of the general population.  Since men with breast cancer are generally in a more advanced stage than women with breast cancer, knowledge of BRCA mutations will be helpful for prevention.  Genetic testing for this mutation is highly encouraged if their is a family history of breast cancer.  

Another article published in through ScienceDirect in 2008 confirms that BRCA2 mutations confer a higher risk in cases of male breast cancer in comparison to BRCA1 mutations.  The BRCA2 protein, in particular, is part of a homologous recombination DNA repair complex that repairs double strand DNA breaks.  This article also explores the variation of incidence of male breast cancer between ethnicities and geographical location.  Investigation of these mutations were conducted in ethnically diverse countries like the UK, United States and continental Europe.  For example, clinical studies revealed only 1% of MBC cases in southern California revealed a BRCA2 mutation while 40% of MBC cases in Iceland showed mutations in the BRCA2 gene.  Although it concluded that increased risk for breast cancer varies among different populations, there seems to be a general overall risk of all cancers studied.  The article concludes that patients must be made aware of self examination techniques and symptoms of the cancers caused by BRCA mutations.  

Recently, an article posted in the the New York Times, discussed a project compiling pictures of males with diagnosed with breast cancer.  The project hopes to raise awareness that male breast cancer does exist.  Young men should not be ignoring a lump on his chest for it could be breast cancer.   

Parker-Pope, Tara. "When Men Get Breast Cancer." Well When Men Get Breast Cancer Comments. New York Times, 24 Feb. 2014. Web. 20 Apr. 2014. <>.

Stoppler, Mellisa. "Male Breast Cancer: Get Facts on Symptoms and Treatments." MedicineNet. MedicineNet, 12 Dec. 2013. Web. 20 Apr. 2014. <>.

"Inherited Gene Mutations." Susan G. Komen®. Susan G Komen, 5 Feb. 2014. Web. 20 Apr. 2014. <>.

Liede, Alexander, Beth Karlan, and Steve Narod. "Journal of Clinical Oncology." Cancer Risks for Male Carriers of Germline Mutations in BRCA1 or BRCA2: A Review of the Literature. Journal of Clinical Oncology, 2004. Web. 20 Apr. 2014. <>.