The lung cancer world now has therapies tied to individual biomarkers, making comprehensive biomarker testing an imperative at diagnosis. On August 18, our monthly Lung Cancer Living Room featured Dr. Benjamin Levy from Johns Hopkins University/Sidney Kimmel Comprehensive Cancer Center for a discussion on “New Biomarkers/New Therapies and the Importance of Knowing Your Cancer.”

If you missed the live event, don’t worry. The key takeaways are recapped below:

What is a biomarker?

We can think of biomarkers as helping us understand the underpinnings of cancer at the gene level. By knowing what genes are altered in a tumor, we can look for tailored therapy for the patient.

Dr. Levy described two types of biomarkers:

  1. Molecular (genomic) testing shows us gene (DNA) level alterations and points to targeted therapy.
  2. PDL1 testing points to proteins on the cell surface which might point to immunotherapy.

As our understanding of these alterations expands, we also now recognize that there are even subsets within mutations (such as EGFR T790M or KRAS G12C). Patients should ask to see their reports.

How is testing done?

We can test tissue and we can test blood, commonly referred to as a “liquid biopsy.” Liquid biopsy technology is improving and is a great complement to a traditional biopsy when there is not enough tissue or repeat biopsies are not feasible. Most people still prefer to test tissue and blood in parallel when possible, as a negative liquid biopsy result will require confirmation with tissue testing.

Heterogeneity refers to the fact that not all the cells within the tumor will necessarily express the alteration that may be driving the cancer. This variability may impact testing results.

 Is biomarker testing recommended at all stages?

While we still don’t know the impact of using targeted therapies in early stage disease on overall survival, studies have pointed to the growing importance of performing comprehensive biomarker testing on patients at ALL stages of disease. An example can be found in a recent study called “ADAURA” that looked at use of the EGFR targeted therapy, osimertinib, for patients with early stage NSCLC.

 What is the difference between a limited panel and comprehensive testing?

There are optimal ways to test. In the early days, doctors used a limited panel including a handful of genes (EGFR, ROS1, ALK, KRAS). Now, with next-generation sequencing (NGS), we can screen for over 300 genes at once. This is commonly known as “comprehensive genomic profiling” or “comprehensive biomarker testing” and allows us to find the right treatment for the right person at the right time.

What advances are occurring in the biomarker space?

Many new markers have been identified (RET, MET, NTRK, HER2, KRASG12C) for which we have new approved drugs or promising therapies in development. The rapid pace with which we are identifying new targets reinforces the importance of comprehensive testing so that we can match patients to approved drugs or to promising clinical trials of new therapies in development. It is important to note that clinical trials may provide better options for patients than traditional chemotherapy.

What about the potential toxicity of immunotherapy treatment prior to starting a targeted therapy?

Since it is possible that previous immunotherapy treatment may induce toxicity when switching to a targeted therapy, we recommend that patients undergo a 2-4 week “washout” period to remove traces of the immunotherapy drug prior to starting on a new targeted therapy.

For additional information on biomarker testing, contact our LungMATCH specialists at 1-800-298-2436 or support@go2.org. Download our biomarker testing flyer for an easy overview.

Every month our Lung Cancer Living Room brings hope, education, and connection home to patients and their loved ones. Through live stream presentations by lung cancer specialists, physicians and researchers, we cover everything from early detection and treatment options to lung cancer taboos and stigma. You can view past Lung Cancer Living Room recordings through our online video library.