Mutation testing is a subject near and dear to my heart. I can’t say how many people I have met who have lung cancer but know nothing about genetic testing. As a matter of fact, not so long ago, I didn’t know much about it either. (And, to tell you the truth, I’m still far from an expert. But, I know enough to tell you that the testing is very important and it can be a life or death test.)
So, What is Mutation Testing?
Mutation testing has a bunch of different names: molecular profiling, molecular tumor testing, biomarker testing, genomic testing, testing for gene mutations, genetic testing, genetic mutation testing, and more. It can be very confusing, for sure. But, here’s what you need to know – if you have lung cancer, especially nonsmall cell lung cancer (NSCLC), you are doing yourself a big favor if you ask your oncologist to get mutation testing, by whatever name, done.
Why is mutation testing important? Our cancer is unique to us. Each tumor cell is made up of specific proteins and molecules. According to American Cancer Society, normal cells do not have mutations, cancer cells do. Genetic testing allows doctors (pathologists) to take a detailed look at tissue from your tumor to see what mutations exist in its DNA and exactly what proteins are present.
How is Mutation Testing Done? Does It Hurt?
No. Or, it doesn’t hurt if you have tissue available from your previous biopsy. The pathologist will just use some of that tissue to do further tests.
If you do not have enough tissue left from your biopsy or the tissue is old, it will be necessary to get more tissue. Depending on where the tumors are located, the procedure could be simple or a bit more involved. I had a tumor on my supraclavicle lymph node (collarbone) so it was very simple to take tissue from it for further testing.
Why is It Important to Have My Tumor Tested?
Your tumor was already tested to a certain degree. The pathologist took the tissue from your biopsy and used it to determine what kind of cancer you have. If you have nonsmall cell lung cancer (NSCLC), then the pathologist looks at the tumor a little closer to determine what subtype it is. Generally, you will learn that you have adenocarcinoma (about 40% of NSCLC cases) or squamous cell (epidermoid) carcinoma (25-30% of NSCLC cases), but you may have one of the less common types, large cell (undifferentiated) carcinoma, adenosquamous carcinoma, sarcomatoid carcinoma, etc..
Your oncologist uses the information from the pathologist to determine a treatment plan that will be the most effective against your tumor type. Recently, it has become more affordable to provide the oncologist with even more information about your tumor type so that he can hone your treatment plan further.
Depending on the characteristics the pathologist finds in your tumor, your oncologist may decide that there are targeted therapies or immunotherapies that likely will be most effective against your tumor(s). In (very) simple terms, targeted therapies attack just your tumors, instead of all of your cells like chemotherapy does. Immunotherapy works with your own immune system so that it can see and destroy the cancer cells.
According to Memorial Sloan Kettering Cancer Center, about 60% of adenocarcinoma lung cancers will have specific mutations. Many of these mutations may have targeted therapies or immunotherapies available to treat them.
Among the most common mutations for which there are targeted therapies are Epidermal Growth Factor Receptor (EGFR), Anaplastic Lymphoma Kinase (ALK), ROS1, and T790. Scientists are discovering more and more mutations every day and finding treatments that work effectively against them. Immunotherapy works best when there is a large amount of a protein called PD-L1 in your tumor.
I’ll take this time to make a brief plug: more, more, MORE money is needed for lung cancer research. We’re talking lives here!!!!