Genetic Tests

Genetic testing can mean several things. Testing a patient’s melanoma for the presence of a BRAF or C-KIT mutation can be done anytime, although it is important to have those results before starting a BRAF or C-KIT inhibitor. Genetic testing is also being investigated in families where 3 or more members have had melanoma. This type of genetic testing has less of a direct impact on the therapies we choose, but it will, some day, help our understanding of why certain people are at risk for the disease.

All patients with stage IV NSCLC who have the most common type, called adenocarcinoma, should have their tumor tested for at least two mutations prior to treatement. These mutations are called EGFR and ELM4-ALK and mutually exclusive (they don't ever occur together). Patients who have the EGFR mutation should be treated with a drug called Tarceva, while those who have the ELM4-ALK mutation should be treated with a relatively new comer, called Crizotinib. This is a new era in lung cancer where we are able to identify a mutation and treat with a drug targeting the mutation, rather than standard chemotherapy. Keep in mind only 15% of patients with adenocarcinoma will have the EGFR mutation and even less have the ELM4-ALK mutation (3-5%), so chances are that you will not have the mutation. Once the mutation is identified and you are treated with the appropriate drug, the mutation does not need to be tested again. That said, there is a significant interest in rebiopsying patients who progress (their tumor grows) on the drugs mentioned above (Tarceva or Crizotinib) to see if the mutation in the tumor has changed to something different. This is being done in clinical trials but is not, to date, considered the standard of care. So, in short, once your tumor has been identified as having the mutation and you are started on the drug, it does not need to be tested again unless part of a clinical trial and you progress on the drug.

It is certainly not too late to be tested. BRCA 1 and 2 testing can be done on DNA extracted for a blood sample or from a buccal swab. NCCN guidelines for who should be offered testing were updated in April 2011. Generally if the guidelines are followed, insurance will cover the testing.

Myriad will provide testing kits to a doctor's office to facilitate the sample being sent in.

This is a very personal reply to a very difficult question. Again, not a doctor but going from my own personal experience with the test.

First of all, the genetics people tend to prefer to test someone who already has a cancer diagnosis. If their test is "clean" then a genetics counselor would probably advise against testing (unnecessary).

Having said that, in my own situation, I was dx'd with an invasive breast cancer in 2006. I was under 50 and my mom was a "survivor" who was also under 50 at dx (of her first BC).

I did counseling and BRCA testing because I had a cancer diagnosis. BOTH of my genes are mutated. They are of "unknown significance" and may be close to be classified as "non cancer causing." When my test came back with mutations, my mom was tested. HER test? NO mutations at all.

If you know there is a mutation in someone who had BC and you choose to have the test, I would suggest absolutely discussing with a genetic counselor. It's important you understand the ramifications of the test results and how they might cause emotional issues, if for example, you tested positive. This is a slippery slope. Some people prefer to NOT know and just continue the recommended screening for their situation. Others (me) need every detail.

Good luck to you.... I have a huge family cluster and no known mutation. My daughter is at a very high risk without the mutation. This is scary stuff.

AnneMarie

You will learn if you have a gene mutation on BRCA1 or 2. Just b/c you are negative does not mean you do not have some type of genetic predisposition for breast cancer, just means you do not have that specific mutation.
Check out my section on BRCA as its very informative
http://www.mybreastcanceranswers.com/brca/brca

Heather
www.mybreastcanceranswers.com

Thank you! I first found my lump while lying on my bed doing a self-breast exam. Since my mom was a breast cancer survivor, I did self exams occasionally, but never thought I would actually find a lump. At first, I didn't believe I actually had a lump. I didn't know what a lump would feel like, and since I was only 27, I thought for sure it was probably just a normal part of my breast. But when I went to the gynecologist for a different health issue, he was very concerned about my lump.

I personally did not have the test for a genetic mutation. My mom went through testing just months before she died, and the tests did not find any mutations that are currently known about. I discussed the results with my oncologist, and he agreed with my mom's genetic counselor that I do not need to have genetic testing since my results would be the same as my mom's testing.

When you've watched every other woman in your family be diagnosed with and treated for breast cancer, you just know that your risk is not average or random. Despite that, it took a good deal of time and insistence on my part to convince my siblings to undergo testing with me. Ultimately, 5 out of 7 of us (including me) were confirmed to be BRCA2 carriers. We all respond differently. Some of my siblings just didn't want to know.

My mother was determined to be BRCA2 positive after her cancer diagnosis, so I knew I was at risk for being positive as well. While in the process of deciding if I wanted to be tested for the mutation, I was diagnosed with breast cancer myself. My oncologist highly recommended the test to determine my treatment path. This added a few weeks to the "waiting" time before my surgery, but knowing the outcome of the test was critical for determining my treatment plan. Of course, I did indeed also test postitive for the BRCA2 gene mutation. I also blog about BRCA at www.nancyspoint.com