Genetic Testing

I had an appointment on Thursday to discuss genetic testing. I am told it will help identify other treatment options as we move forward. Our insurance may cover it in its entirety because of my current diagnosis. We'll see. I can still opt out if they don't cover it.

If any of you have done any cancer genetic screening, then you may be familiar with the company. It is Invitae, genetic testing for hereditary cancer. To be honest, I doubt if any of my cancer is related to genetics. I could be wrong.

Anyway, they test for 47 different genes, nine for breast cancer alone.  Here are the 47 genes they test for:

APC, ATM, AXIN2, BARD1, BMPR1A, BRCA1, BRCA2, BRIP1, CDH1, CDK4, CDKN2A, CHEK2, CTNNA1, DICER1, EPCAM, GREM1, HOXB13, KIT, MEN1, MLH1, MSH2, MSH3, MSH6, MUTYH, NBN, NF1, NTHL1, PALB2, PDGFRA, PMS2, POLD1, POLE, PTEN, RAD50, RAD51C, RAD51D, SDHA, SDHB, SDHC, SDHD, SMAD4, SMARCA4, STK11, TP53, TSC1, TSC2, VHL. 

The genes specific to breast cancer are ATM, BRCA1, BRCA2, CDH1, CHEK2, PALB2, PTEN, STK11M and TP53. Other than BRCA 1 and 2, the others are foreign to me. I suspect they are foreign to most of you as well.

Let's see if we can shed some light on the subject:

•  ATM - ATM is a DNA-damage response gene that is commonly mutated in cancer. Germline mutations in this gene are thought to contribute to breast cancer susceptibility, and PARP inhibition is currently being studied for it's potential in treating these patients. It has been suggested that women who carry a mutation in the ATM gene have an estimated 20-60% increased risk for breast cancer
• CDH1 - People with HDGC often get a kind of stomach cancer called “diffuse gastric cancer.” This type of stomach cancer is hard to find at early stages, because it does not form a noticeable tumor that can be easily seen with screening. Women with HDGC have a high risk for a type of breast cancer that forms in the lobules of the breast. This is different than the more common type of breast cancer that starts in the milk ducts. It is recommended that women with CDH1 mutations start their breast screening at age 35 or earlier if they have relatives who had breast cancer at younger ages. It is also recommended that this screening include MRIs in addition to mammograms.
• CHEK2 - Women with mutations in the CHEK2 gene have an increased risk for breast cancer, sometimes at relatively young ages. This increase in risk is not as high as what is seen in women with mutations in the BRCA1 and BRCA2 genes, but it is high enough to consider ways to reduce cancer risk and to increase screening in an attempt to find any breast cancers that do develop as early as possible. A woman who has a CHEK2 mutation, and who has already had breast cancer, has a high risk of developing a second breast cancer within the next 5 to 25 years. Men with mutations in the CHEK2 gene also have an increased risk for breast cancer. This risk is much smaller than the risk for women.
• PALB2 - The PALB2 gene is called the partner and localizer of the BRCA2 gene. It provides instructions to make a protein that works with the BRCA2 protein to repair damaged DNA and stop tumor growth. Women with mutations of the PALB2 gene are at a 58% lifetime higher risk of developing breast cancer.
• PTEN - Phosphatase and tensin homolog (PTEN) is a protein that, in humans, is encoded by the PTEN gene. Mutations of this gene are a step in the development of many cancers.
• STK11 - The STK11 gene (also called LKB1) provides instructions for making an enzyme called serine/threonine kinase 11. This enzyme is a tumor suppressor. People with mutations in the STK11 gene have a condition called Peutz-Jeghers Syndrome, or PJS. People with PJS have a high risk for many different types of cancer, including breast, colon, pancreatic, stomach, small bowel, cervical, and endometrial. 
• TP53 - TP53 or tumor protein is a gene that codes for a protein that regulates the cell cycle and hence functions as a tumor suppression. If you have a TP53 mutation, the gene cannot control the growth of tumors.

Please note I just listed a high level description of the genes and mutation. To learn more, Google is your friend here. There is a lot of information available online that goes into much more detail about the gene and the impact of genetic mutations of these genes.

Fingers crossed that I have no genetic mutations.