Testing for lung cancer biomarkers

Interview with Prof Thomas J. Lynch, MD
Director of Yale Cancer Center,
New Haven, USA

Q. What exactly is a biomarker and why is it important to test for biomarkers?

A. Well, there are several types of biomarkers. Some biomarkers give you a sense of prognosis; they tell you whether a patient might do well or might not do well, independent of how you treat them. Other biomarkers are used to help select treatments and a biomarker like an EGFR mutation is really helpful in selecting what the best treatment for a patient happens to be. Now I think an EGFR mutation is more than just a biomarker because the EGFR mutation explains what makes the cell malignant. It explains that the primary cancer and the primary driving force of what makes that cancer happen. So, if you can inhibit or turn around or turn off that mutated gene, you can see improvements in outcome and patients can do better. They can have less shortness of breath, they can have better quality of life and their tumours can shrink.

Q. Which patients are you testing for EGFR mutations?

A. I believe all patients who are either, have adenocarcinoma or are light or never smokers, I believe all of those patients should be tested for EGFR, ALK, ROS1 and RAS, in my opinion. In addition, at the EL cancer centre we're testing patients broadly for four hundred and fifty different genes. We're doing deep sequencing on four hundred and fifty different genes that are identified in the cosmic database as being related to cancer. So, I take the bias that more testing is better.