Question: I have metastatic lung cancer that is responding well overall to the targeted therapy that I take. However, a few spots in my bones are not shrinking from the treatment. Can radiation therapy help me? 

(Answered by Dr. Daniel C. Schiffner from Sutter Health Palo Alto during his appearance at the September 2024 Lung Cancer Living Room. It has been edited for this use.)

Answer: Yes, possibly. If your systemic treatment (chemotherapy, immunotherapy, target therapies) is working on most of your cancer, but a few spots are not responding as well, radiation therapy could be used to treat those spots. This can allow you to stay on your systemic treatment, which is otherwise working well.

Traditionally, stage 4 (IV) lung cancer was only treated with systemic drug therapies like chemotherapy. If you had – for example – 10 spots and 9 of them responded to the treatment, but 1 didn’t, you were considered a non-responder. As a non-responder, you would be put on a different drug and would never return to that systemic treatment.

Currently, we have developed the concept of “oligoprogression,” which means the cancer progresses in a limited number of sites while most of the disease remains under control. In the patient just described with 10 spots, 9 of which are well-controlled with 1 spot still growing, we can presume that one clone of cells was able to build resistance to the drug.

Drug resistance does not predict radiation resistance, however, so we are now able to zap that one spot with radiation and get it under control. This allows you to continue on your same line of therapy, which is otherwise working well. We can “zap” individual spots multiple times. If you got to the point that all 10 spots were growing, you would probably need to switch therapies. We usually say that 1 to 3 spots – or, at most, 1 to 5 spots – is where we draw the line between oligoprogression and more meaningful progression.

The goal with late-stage lung cancer is to stay on your therapy as long as you can, and radiation therapy can help you do that.

Please note that the information included in any published answer is for educational pursuit only and is not intended or implied to be a substitute for professional medical advice. The reader should always consult their healthcare provider to determine the appropriateness of the information for their own situation. Nothing from GO2 for Lung Cancer should be construed as an attempt to offer or render a medical opinion.