WHAT DOES THIS MUTATION MEAN?
BRCA stands for the BReast CAncer gene. There are two genes, BRCA 1 and 2, with either conferring different amounts of risk for different cancers. Both have about a 50-to-80 percent risk of breast cancer for women, with BRCA 1 having a higher risk of ovarian cancer (20-to-60 percent, as compared to 10-to-20 percent for BRCA 2), as well.
The mutation is inherited in an autosomal dominant fashion, which means only one parent needs to be affected to have it passed onto their child. It also means that multiple family members typically, but not always, are afflicted with the cancers associated
with the gene.
Investigating for the presence of a BRCA mutation may involve a visit with a genetic specialist, who, amongst other things, would produce a detailed personal and family history that maps out disease patterns.
The BRCA genes, as many others like it, are in charge of repairing our DNA as it is being replicated. As I type, I have to backspace to fix misspelled words and form a coherent sentence. This is similar to what a repair gene would do to get the correct sequence of DNA nucleotides. Replicating inappropriately or not dying when it is supposed to. In essence, it can lead to spawning of a cancer cell.
“If the BRCA genes are not working properly, then the sequence of DNA would not be correctly assembled, which can lead to a cell behaving abnormally.”
— Dr. Miguel R. Pelayo, physcian at Space Coast Cancer Center (SCCC)
WHO IS AT RISK?
Although breast cancer does have the highest prevalence, there are other cancers associated with BRCA mutations. Men should not think this is a women only issue. In fact, with BRCA mutations there is an increased risk of prostate cancer and male breast cancer.
The occurrence in the general population is estimated to about 1 in 500-to-1,000. In stark contrast, as much as 1 in 40 in the Ashkenazi Jewish population harbor a BRCA mutation.
It is important to note that less than 10 percent of all breast cancers and less than 15 percent of ovarian cancers are associated with BRCA mutations. That being said, not everyone who would fit criteria to be tested are actually being tested, so those percents could certainly be much higher.
TESTING & TREATMENT
In the management of a patient with breast cancer and a known BRCA mutation, there are some differences in treatment recommendations. Lumpectomy still can be done, but there is a risk of new breast cancers still being present. This also pertains to women who only get an ipsilateral mastectomy.
In a patient with a known mutation and no cancer present, preventative surgeries and other modalities will need to be discussed. Bilateral mastectomy reduces the risk of breast cancer by over 90 percent. If childbearing is completed, salpingo-oopherectomy will need to be offered as well, which decreases the risk for both breast and ovarian cancer. Tamoxifen, an estrogen receptor antagonist, could also be used for prevention to avoid mastectomy, but what has to be considered is that not all breast cancers are sensitive to estrogen.
Interestingly, a BRCA mutation has also been in the news due to its founding company, Myriad Genetics, having a patent since the ’90s on the genes, and thus being the only company to test and study this gene. There is a strong opinion that a company cannot have a patent on something that happens in nature, such as our own DNA. It is argued that DNA is already present and its discovery is not creating, which is what patents typically are meant to protect.
The patent also means that the company can charge what it sees fit for testing patients, as there is no competition from others. The current cost of the test is approximately $3,000, although the company states most patients typically pay around $100. This is currently being reviewed by the Supreme Court, with the monumental decision changing how BRCA mutations will be studied and tested for the foreseeable future.
Dr. Miguel R. Pelayo, a Space Coast Cancer Center (SCCC) physician, graduated from the University Central del Caribe, a U.S. accredited school in Bayamon, Puerto Rico. He completed his residency in internal medicine at the University of South Florida in Tampa. Dr. Pelayo completed his fellowship training in Hematology and Oncology at H. Lee Moffitt Cancer Center and Research Institute in Tampa, Florida. He is board certified in internal medicine and is a member of the American College of Physicians, the American Society of Hematology and the American Society of Clinical Oncology. For more information, call (855) 894-HOPE or visit SpaceCoastCancer.com.
Below are scenarios which would prompt an investigation, as obtained from Cancer.gov:
- Two first-degree relatives (mother, daughter or sister) diagnosed with breast cancer, one of whom was diagnosed at age 50 or younger.
- Three or more first-degree or second-degree (grandmother or aunt) relatives diagnosed with breast cancer regardless of their age at diagnosis.
- A combination of first- and second-degree relatives diagnosed with breast cancer and ovarian cancer (one cancer type per person).
- A first-degree relative with cancer diagnosed in both breasts (bilateral breast cancer).
- A combination of two or more first- or second-degree relatives diagnosed with ovarian cancer regardless of age at diagnosis.
- A first- or second-degree relative diagnosed with both breast and ovarian cancer regardless of age at diagnosis
- Breast cancer diagnosed in a male relative.
For women of Ashkenazi Jewish descent:
- Any first-degree relative diagnosed with breast or ovarian cancer.
- Two second-degree relatives on the same side of the family diagnosed with breast or ovarian cancer.