Genetic Re-Testing: Can Lung Cancer Mutations Change Over Time?

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.

Andrew Schorr:

In lung cancer if Mrs. Jones is seen to have a KRAS mutation, just to pull one out, early on, does that always remain what's driving her lung cancer, or might it change and there might be a need to test again?   

Dr. Sequist:

Who are you asking?  

Andrew Schorr:

Dr. Sequist, first. 

Dr. Sequist:

I think we're all experts in this, so we can everybody chime in as well.  If the cancer truly has a driver oncogene what that means is that every single cancer cell in the tumor carries that genetic mark.  Probably the very first cancer cell that came up in the body had it, and then every daughter cell that was created afterwards carries this mark.  As patients—so typically these are EGFR, ALK, ROS, MET, RET.  These are the ones that we have targets for, BRAF, targeted drugs. 

Now, once a patient is on a targeted drug you can think of it like evolution, like survival of the fittest. So a drug is exerting pressure on the cancer, many cells are dying, but sometimes a cell will have a certain characteristic that allows it to live through the drug treatment, and then from there a resistant tumor can grow.  And so second mutations or second pathways can become activated after patients have been treated with certain drugs.  And the more drugs that people have been exposed to over time the more different subpopulations that might have varying signatures come up.  

But you never lose that original mutation.  It's something that is always carried forward.  It's just what else piles on top of it across the different arms.  I describe it as different arms of the family or cousins.  Like this tumor is a cousin of that tumor because they do have some different characteristics but still that same core characteristic.  

Andrew Schorr:

And you were saying about retesting?  

Janet Freeman?Daily:

So some drugs we know that if they stop working there's another drug that you can go to, but as we develop more and more drugs and EGFR, with which Dr. Sequist is very familiar, has more drugs than the rest of us.  When patients take certain of those drugs second or third line they actually might develop a different mutation and will have to get retested to find out how to treat that.  We're right on the forefront of learning about how the genomics of cancer works, and we learn new things all the time.  

Andrew Schorr:

So, Jess, you and your sister have sought out eminent specialists at major centers, but, as you said, not everybody goes there.  What advice do you have to patients and family members, especially family members, because sometimes the patient is so terrified just being led through care and the family member has to pick up the mantle?  What would you say so that the loved one gets the best care?  

Jessica Wittebort:

For us the most profound change has been to find a specialist at an academic institution.  I think if you don't—if you're not able to do that, it is really important to find your patient group and start asking, what are they doing.  What information can you get your head around?  And keep your head above water, because I really do believe there's so much hope and there's so much energy right now and momentum in this space that it's important to just keep finding, keep looking for the information.  And if you're not getting the answers that you need or are too complicated figure out a way to not feel shy about asking again. 

Please remember the opinions expressed on Patient Power are not necessarily the views of our sponsors, contributors, partners or Patient Power. Our discussions are not a substitute for seeking medical advice or care from your own doctor. That’s how you’ll get care that’s most appropriate for you.