Biomarker testing is a critical component for identifying genetic mutations and resistance mechanisms for patients with non-small cell lung cancer (NSCLC). We had the honor of hosting Mass General Cancer Center’s Dr. Jessica Lin for a webinar on how advancements in biomarker testing are transforming the landscape of lung cancer care and treatments.
You can watch the full informative discussion below.
Keep reading for some key points transcribed from the webinar.
The following questions and responses have been lightly edited for grammatical purposes.
1) Could you address any myths about lung cancer or molecular biomarkers and lung cancer?
Yes, that’s an excellent question. One thing I always like to start off with is that lung cancer can affect anyone with lungs.
Today, there are a lot of misconceptions about how lung cancers only affect patients who have heavily smoked cigarettes. This is a stigma that many patients and families affected by lung cancer have to live with and it is simply not true. In fact, many patients that I treat in my clinic have never touched a cigarette in their entire lives. We’ve learned over the years that certain subtypes of lung cancer are more common in patients who have never smoked before.
Another myth that I hear a lot from patients is a concern and worry that if you’re seeking a second opinion or consultation with an expert in the field, your primary oncology team or your doctor may take offense or view it in an unfavorable way. That is simply not true. I think in the oncology community, we always encourage second opinions. We’re always communicating with each other and asking other oncologists for thoughts and input for your care. You should feel empowered to ask for second opinions and get consultations, particularly when you’re initially diagnosed with lung cancer, but also during the course of treatment. If you need to change therapy or are at a challenging point in your cancer therapy, it’s always good to consider a second opinion.
2) What is biomarker testing and how does it help identify specific mutations for the cancer and alterations that influence cancer growth? How does biomarker testing or genomic testing differ from genetic testing?
If we take a step back, it’s critical to understand that lung cancer is not one disease. Lung cancer is very much a heterogeneous illness that’s comprised of many different subtypes which all have distinct characteristics and distinct biology.
The term biomarker testing refers to testing a patient’s specific lung cancer for either the presence or absence of alterations in different genes or for the level of expression of certain proteins that we know are important in understanding the cancer’s biology and helping determine the optimal treatment. Biomarker testing has become an essential part of the initial diagnosis of lung cancer and in treatment decision-making.
Biomarker testing refers to not just gene testing on the cancer, but also other testing like looking at protein level expression. As an example, we perform testing looking at the level of a protein called PD-L1. This is a really important protein in lung cancer, diagnosis, and management because it can tell us how likely it is that a patient’s lung cancer will respond to a form of medication called immunotherapy. PD-L1 expression testing is not part of gene testing. Gene testing is looking for mutations or structure changes across cancer-related genes. A truly interchangeable term for biomarker testing in lung cancer may be “molecular testing” rather than genetic testing.
Another distinction I want to point out is that sometimes people use the term genetic testing to refer to testing for hereditary gene changes or mutations, meaning the changes in genes that are passed down from your parents to yourself, or perhaps to your children or any kind of blood-related relatives. That is a very specific kind of blood genetic testing. More broadly when we say genetic testing, it can be done to look for not just hereditary mutations using blood samples, but it can also look for non-hereditary cancer-specific mutations. It can be done using either a blood sample or a tumor sample that’s taken through a needle biopsy, for example.
3) When are biomarker tests conducted and should patients ask about them in early-stage lung cancer?
When you’re initially given the diagnosis of lung cancer, that is a critical time for doing biomarker testing. For many years, national guidelines, including the NCCN Guidelines®, which is what the oncologists refer to as the standard of care, have recommended biomarker testing for every patient newly diagnosed with advanced-stage or metastatic non-small cell lung cancer. That’s kind of old news.
More recently, biomarker testing is also recommended and part of routine care for patients diagnosed with earlier-stage non-metastatic lung cancer. That includes patients with stage I to stage III lung cancer. The reason that these guidelines have been expanded for biomarker testing is because we’ve learned that these results impact post and pre-operative care and also for patients who received chemo/radiation for stage III lung cancer.
There have been studies done in recent years looking at how successful we are in actually doing the biomarker testing and the statistics have been sobering. There are many patients to date, even those with metastatic lung cancer, who don’t get the right panel of biomarker testing performed. In some studies, the rate is 50% or lower of patients getting the biomarker testing they need. All that is to emphasize that it’s important to be aware of the recommendation for biomarker testing in lung cancer and to make sure it is done.
I would say patients should absolutely bring it up and ask about biomarker testing with their doctors. You should feel empowered to do this. There may be a reason that it’s not done, but if you don’t ask about it, you will not understand why. I would absolutely encourage you to talk to your doctors about biomarker testing.
4) What are some reasons a physician would not recommend or bring up biomarker testing?
I think in terms of new therapies and the panel of biomarkers available, guidelines are evolving so fast in lug cancer. Sometimes there is a delay in the adoption of the new guidelines, especially out in the community.
For example, for many years we’ve known that EGFR and ARC are actionable gene alterations in lung cancer that we can match to 30 therapies. I would say EGFR and ARC are more commonly tested than some of the newer targets that have been identified like MET exon 14 skipping, HER2 mutations, or even KRAS mutations. Depending on how much is known about the specific biomarker, the rate of testing varies.
It also has a lot to do with the practical challenges of biomarker testing. Not every patient has a tumor that is easily accessible and safe for biopsy. Some patients may have lots of small, long modules not big enough for biopsy. Some patients may present with a lot of cancer burden, but they may all be concentrated in the brain, for example. Brain biopsies are super invasive, so it’s not always doable. Other times a biopsy is successfully performed and we have the diagnosis of lung cancer, but there is not enough tissue left over to do all the biomarker testing like gene sequencing.
It also may not be affordable which could lead to hesitation in making sure all the biomarker testing is done. These are some of the more common reasons I’ve come across when I’m seeing second opinions of patients who haven’t had all the biomarker tests done.
Watch the full webinar with Dr. Lin here.
