Dr. Erin Schenk, a lung cancer specialist, provides an in-depth explanation of what immunotherapy is, and its role in treating lung cancer.
Dr. Erin Schenk is an assistant professor in the division of medical oncology at the University of Colorado Anschutz Medical Center. Learn more about Dr. Schenk and her lung cancer research here.
Dr. Erin Schenk:
Immunotherapies are powerful new medicines that we available to us as medical oncologists and especially within patients with lung cancer. Immunotherapies are medicines that help to activate your body’s own defenses to go seek out and kill the cancer cells.
So, immunotherapies prevent stop signs on the cancer cells.
What happens is that as the cancer cells grow and as they become more resistant to your body’s natural defenses, it puts up certain stop signs. And these stop signs prevent your body’s immune system from attacking them. Immunotherapies, basically, it cuts off that stop sign so that your immune cells can go and attack the cancer cells.
Immunotherapies play a role in the treatment of many lung cancer patients, nearly all. So, immunotherapy has recently found a role in curative-intent therapy meaning we give these treatments to you to try and cure you of your cancer completely. And that’s in patients who have advanced lung cancer that they can’t surgically resect, or it’s not safe or feasible to cut out, but it hasn’t spread to anywhere else in the body.
So, often, those patients receive chemotherapy and radiation together, and then they receive immunotherapy for a year. So, that’s one set of patients we treat with immunotherapy. And then most other patients with lung cancers especially metastatic lung cancer or cancer that’s spread elsewhere in the body, immunotherapy plays a role in treatment regardless of what type of lung cancer that you have with a couple exceptions which I’ll get to.
So, first, if patients have small cell lung cancer that has spread in other parts of the body, immunotherapy’s an important part of the initial treatment regimen combined with chemotherapy. That’s one of the first advances in decades for patients with small-cell lung cancer. The other situation where we use immunotherapy in metastatic disease is with non-small cell lung cancer. And here we have data and studies to support the use of immunotherapy either alone or in combination with chemotherapy medicines.
And the determinate, there’s a number of factors we use to help determine whether a patient can get immunotherapy alone or immunotherapy in combination with chemotherapy, that’s based on PD-L1 status. So, that’s the immunotherapy marker that we look for on cancer cells. If the PD-L1 status is high enough on the cancer cells, we can discuss with our patients using immunotherapy alone.
If that PD-L1 marker on the cancer cells is not high, then we can use immunotherapy plus chemotherapy in our patients. One area where we’re still not quite sure how to best use immunotherapy are in patients with driver mutations or some of these mutations that we look for with special molecular testing like EGFR, ALK fusions, ROS1 fusions.
What we’ve been learning over time is that immunotherapy alone does not appear to help patients do better for longer. We’ve also been learning through clinical trials that immunotherapy combined with TKIs which is the targeted therapy patients receive if they have one of these driver mutations, that does not appear to be effective or safe from some of these early clinical trials.
There’s some debate right now amongst my national/international colleagues as to whether or not giving immunotherapy plus chemotherapy is the right choice for these patients after TKIs or targeted therapies stop working. It’s really up to the discussions that you have with your doctor and whether or not they think immunotherapy and chemotherapy could be right in that situation.