Immunotherapy: Harnessing the Body’s Own Healing Power to Fight Cancer

One of the most promising tools in an oncologist’s toolbox is immunotherapy. This treatment boosts the body’s own immune system so it can effectively destroy cancer cells. Immunotherapy has proven very effective in certain cancers, such as some melanomas and lung tumors. While immunotherapy is still unavailable at many community hospitals, it has been prescribed at Marin General Hospital for several years, with encouraging results.

Learn more as Marin General Hospital oncologist Dr. Barbara Galligan explains immunotherapy and how it works. Topics covered include how the treatment is administered, who is a good candidate, and potential side effects.
Immunotherapy: Harnessing the Body’s Own Healing Power to Fight Cancer
Featuring:
Barbara Galligan, MD, MPhil
Patient-centered care drew Barbara Galligan, MD to MCC, where she is inspired every day by her patients and colleagues. Prior to medical school, Dr. Galligan worked for 10 years in the tech industry writing content and designing data models and information architecture. She also worked in medical research at the University of California Berkeley and at Memorial Sloan Kettering Cancer Center in New York. Dr. Galligan’s combination of scientific research and a liberal arts education helps her relate to her patients and learn from her work.

Learn more about Barbara Galligan, MD
Transcription:

Bill Klaproth (Host): Immunotherapy has become an important part of the fight against certain types of cancers, so how might this impact you or a loved one? Here to talk with us about immunotherapy is Dr. Barbara Galligan, medical oncologist and hematologist at Marin General Hospital. Dr. Galligan, thank you for your time today. So let's start at the beginning. Can you explain to us what is immunotherapy?

Dr. Barbara Galligan, MD, MPhil (Guest): Sure, so immunotherapy is a collection of treatments that oncologists have at their fingertips to treat cancer patients. Immunotherapy in some senses has been around for a long time. For example, simple vaccines can be thought of as immunotherapy because they're a way for your body to rev up its immune system to fight infection. Today there's newer forms of immunotherapies in the form of antibodies and what we call checkpoint modulators which are medications that also rev up the immune system to fight cancer.

Bill: So you're basically using your own immune system to fight the cancer. Is that right?

Dr. Galligan: That's right. Our immune systems are active every day and scanning our bodies to find any cells that might be abnormal, cancer cells being a type of abnormal cell. And what can happen is two things; one is the immune system can be suppressed and lose its ability to find and track out any potential cancer cells in the body, or there can be a cancer that grows and outsmarts the immune system and basically says to the immune system, "Ignore me, I'm not a cancer," and these immunotherapies can reverse that process.

Bill: So this is really interesting. How does this work? How do you tell the immune system, "Okay I need you to turn on and go after this cancer cell"?

Dr. Galligan: Right, well there's a lot of different types of immunotherapy. The ones that are getting the most press right now are called checkpoint modulators, and they're called that because our immune system has checkpoints on it. If the immune system was functioning at full blast all the time, it would be too active. It would basically start attacking healthy cells and healthy tissues. That's how things such as autoimmune diseases develop. However, cancer cells are aware that there are these checkpoint brakes on the immune system, and cancer cells have sent out signals that can actually put the brake on the immune system. What some of these checkpoint modulators do is they take the foot off the brake of the immune system and unmask the cancer cells.

Bill: Taking the foot off the brake. What a great analogy and a great visualization of this. And Dr. Galligan, this is very personalized, right? It's not like one size fits all, you dial this in for the specific person.

Dr. Galligan: Well there are some treatments now in cancer that are very personalized, meaning that the tumor tissue that's taken out of a particular patient at the time of diagnosis gets tested for abnormalities, and then we try to match our treatment to that testing. Immunotherapy isn't always strictly personalized. There are sometimes when we might check the tumor itself and see does it have a marker? Is there something on that tumor tissue that suggests to us that immunotherapy might be effective in treating this cancer? But unfortunately, we don't have a test that's 100% accurate yet. Sometimes there are patients and we'll test their tumor, and we'll say, "Wow this patient looks like he or she will respond to immunotherapy," but they won't. Or there will be patients that have a marker and we think, "Wow this patient is going to have a robust response to immunotherapy," and they don't. So it's not always 100% personalized. We don't always know in advance if the treatment is going to work for the patient.

Bill: Okay gotcha. So who is a good candidate then for immunotherapy?

Dr. Galligan: In order to determine if someone's a good candidate for immunotherapy, they need to have a good working relationship with their oncologist. It's a very nuanced and complex field, and making the decision if immunotherapy is right for treating a particular patient involves both - number one, what type of cancer is it? There are some cancers that do seem to respond to immunotherapy and some cancers that don't. And number two, what is the person's personal medical background like? There are some patients, for example patients with autoimmune disease, who may not be eligible for immunotherapy. So it's a very complex decision making process.

Bill: So Dr. Galligan, does immunotherapy work better on certain types of cancer?

Dr. Galligan: Yeah, so the poster child for immunotherapy was melanoma. So melanoma was one of the first cancers that was studied for treatment with immunotherapy, and many melanoma patients will respond to immunotherapy. But to put this in perspective, even in the best case scenario, only about 30% of patients with melanoma will have a response and the percentages really fall off from there. In lung cancer it's probably about 20% to 25%. In head and neck cancer, for example, even less. So it's very much a decision that needs to be made between the oncologist and the patient, if immunotherapy is the best option. There are a lot of types of cancer out there that are better served being treated with something other than immunotherapy because they're just not that responsive.

Bill: So for someone who does qualify and chooses the option of immunotherapy, how is it administered?

Dr. Galligan: There are different types of immunotherapy. The one we've been speaking about the most, these checkpoint inhibitors, are administered intravenously through one of the patient's veins in an infusion room. The other types of immunotherapy, things such as vaccines and antibodies, some are administered by a shot. So it really again depends on which type of immunotherapy the patient receives.

Bill: And how does the process work? Is it like chemotherapy? Do you go in for multiple visits?

Dr. Galligan: That's exactly right, it is similar to chemotherapy. You go in for multiple visits, you sit in a chair in an infusion room, and the medication runs in through the intravenous into your veins for a period of time, sometimes it's an hour, sometimes it's longer, and then you go home and you return on a set schedule every few weeks. An important part of it is that with each return visit you're seen by a physician and examined to see if you're developing any of the side effects associated with immunotherapy so that those side effects can be caught early and treated.

Bill: So what are some of those side effects?

Dr. Galligan: Because immunotherapy ramps up the immune system, it can also make the immune system turn on your own healthy tissue. So for example, some patients get severe diarrhea called colitis because their immune system has been so ramped up that it starts to degrade the lining of the colon, and the patients develop diarrhea. Any organ in the body can be negatively impacted by immunotherapy including the liver, patients can develop a hepatitis. In the lungs, patients can develop a pneumonitis, and their hormones can also be impacted, things like their thyroid hormone can be impacted by immunotherapy. So all of these things need to be carefully monitored when a patient is receiving treatment.

Bill: And is immunotherapy commonly available at community hospitals?

Dr. Galligan: That depends. We have immunotherapy available here at Marin Cancer Care, and it's coming more and more into the mainstream, but there are places in the country where immunotherapy is not available.

Bill: Now Dr. Galligan, if you could look into your crystal ball for me, is immunotherapy, the future of cancer care?

Dr. Galligan: I think immunotherapy is a very important part of the future of cancer treatment, however, oncologists caution that you never put all your eggs in one basket. We've learned in the past when new therapies have come out, for example the anti-angiogenesis therapies - those were therapies directed at how vessels grow to feed the tumor - there was a big splash around those, and now they're used sort of modestly. I think the same will be true of immunotherapy. I think we have a lot more to learn, I think we can use it more widely in the future, but oncologists will always need to have a toolbox with multiple tools in it to treat cancer because cancer is such a complex disease.

Bill: Right, so for right now this is just another tool in the fight against cancer.

Dr. Galligan: Absolutely, and that's why working closely with your doctor is important, because we like to use several different tools to go after the cancer rather than just focus on one.

Bill: So Dr. Galligan, you were mentioning earlier about percentages, but even say a 30% chance, that really does give somebody hope.

Dr. Galligan: Absolutely, and the great story about immunotherapy is that it's showing to be effective in cancers that have been traditionally very hard to treat. Melanoma, for example, was almost universally a very deadly cancer, and we didn't have a lot of good treatments for it. So it is truly miraculous that we now have a therapy that will drive some of these patients into remission. And the other great side of immunotherapy is that remissions can be very long-term. We have patients who are receiving several years of benefit from receiving immunotherapy.

Bill: Such good news and important research happening. Dr. Galligan, thank you so much for your time today, we appreciate it. For more information and for health tips and information for Marin General Hospital, please join Health Connection at www.MarinGeneral.org/healthconnection. That's www.MarinGeneral.org/healthconnection. This is The Healing Podcast brought to you by Marin General Hospital. I'm Bill Klaproth, thanks for listening.