My presentation talked about the role of radiation therapy with immunotherapy. Immunotherapy has emerged as the greatest novel treatment for cancer today. However, the approaches with immunotherapy affect only a minimal number of patients and the results can be short-lived. So we explored today how the role of radiation can add to the benefits of immunotherapy or, vice-versa, how immunotherapy can add to radiation.
What are the benefits to using this combination approach?
Radiation therapy, in and of itself as a monotherapy, can stimulate the immune system. It does that in a number of ways. One, it can increase what’s called the major histocompatibility complex, or MHC, and it does that, the MHC picks up the tumour antigens and they present them to the T-cells that say, ‘Hello, I’m sick, come and help me.’ Radiation has a very big part in making the MHC visible. Tumours are very good at hiding it or suppressing it, where radiation can play a very important part in making it visible so that the tumour can pick up the antigen so that the immune system knows that it’s sick and can wage an attack on the cancer cells. Also radiation is very important because it causes what’s called an abscopal effect. Abscopal comes from the term target and a distance, so abscopal – distant target. Radiation causes such an immune response by destroying a tumour that it wages a war on cells that are elsewhere in the body. So a tumour, if we treat something in the lung we treat it locally with a high dose of radiation, it elicits an immune response. Those immune cells then go and target tumours elsewhere in the body.
Why is it important for oncology nurses to be aware of this?
When we combine therapies sometimes we’re combining toxicities. We saw this in the case with radiation and chemotherapy, putting the two together sometimes combines the toxicities in these patients. This becomes very important for oncology patients as we start to combine immunotherapy with radiation therapy we may see a rise in toxicities such as pneumonitis and colitis and dermatitis because we’re combining the two therapies together. So as nurses we need to be very aware of what these toxicities are and how combining the two together can potentiate these side effects in patients.
How do you see the combination of immunotherapy and radiation being used in the future?
Immunotherapy plus or minus radiation therapy is very new, it’s very novel. So adding radiation therapy to the mix, there’s about 100 clinical trials going on right now to see the benefits, the timing of the radiation, the dosing of the radiation, what tumours will be more effective. So in the future I see, just like we do with chemo and radiation, I see the combining of radiation and immunotherapy. You’re going to have an immuno-radiosensitisation so immunotherapy will sensitise the radiation to become more effective and radiation also will cause the immunotherapy to also be more effective. So your future is going to be the combination of the two agents, whether that’s concurrently, whether that’s in an adjuvant setting we’re not sure yet, that’s what the clinical trials are for.
Any interesting questions, concerns or feedback from the session?
One of the big questions that people have is when you are using immunotherapy in these patients and you can elicit certain side effects, immune responses, where does the role of steroid therapy come in to these patients? Radiation therapy can cause a lot of inflammation, especially if you’re treating something like a brain tumour you can have a significant amount of inflammation which requires a dose of steroids in these patients. But being on immunotherapy you don’t want to give the steroids because you don’t want to immunosuppress. So a lot of the big questions are what is going to be the interplay between dealing with the side effects from radiation therapy but not suppressing the immunotherapy.
What is the take home message for oncology nurses?
The take home message is immunotherapy is very effective but it can be even more effective with the addition of radiation therapy. The two work very synergistically, one will definitely enhance the other and what you are going to see is a future of radiation and immunotherapy combined.