Surgery and Radiation in Small Cell Lung Cancer
Kristie L. Kahl: How does chemo play a role in tandem with other types of treatment like surgery and radiation?
Wade T. Iams, MD: Chemotherapy in combination with radiation or surgery typically plays either an amplifying role in the case of radiation where we combine the 2, often at the same time in order to maximize cancer cell death, with a goal for curing cancer, or to alleviate or eliminate any cancer cells that may be left over after surgery. So in individuals with small cell lung cancer, where chemotherapy plus radiation, or surgery followed by chemotherapy, our options, those individuals have stage 1, 2, or 3 disease where our goal is to cure them. And the relationship of chemotherapy with those treatments is to either amplify in the case of radiation, or to eliminate any leftover cancer cells in the case of surgery.
Kristie L. Kahl: With surgery, what would make a small cell lung cancer patient a candidate for surgery?
Wade T. Iams, MD: The key components that determine whether an individual with small cell lung cancer is eligible for surgery are the size of the tumor and spread of the tumor. Individuals with small cell lung cancer are at very high risk of having cancer cells spread throughout the body even before we're able to see them on scans. So we typically reserve surgery in individuals with small cell lung cancer, if there's only 1 spot of cancer that's less than 5 centimeters. With that, when we look back at patients over time, we feel at least moderately confident that at that size, it's unlikely but not impossible, that those individuals would have cancer cells elsewhere in their body. And going after that cancer with surgery makes sense as long as it has not spread.
Kristie L. Kahl: What would make an individual a candidate for radiation?
Wade T. Iams, MD: Individuals with small cell lung cancer are eligible for radiation in combination with chemotherapy if the cancer has not spread outside of the lymph nodes next to the lung where the cancer started, and then within the lung where the cancer started, and it's the same logic that is applied to who's eligible for surgery, with a little bit broader eligibility. Individuals are eligible for chemotherapy and radiation if we suspect that we can treat all the areas of the cancer in their body with the radiation and chemotherapy to amplify that effect of radiation, when the cancer has spread outside of the lung that it started and the lymph nodes right next to it, in other words to the other lung, or to the liver, or to bone or brain, which are common sites for small cell lung cancer to travel to. We typically do not recommend chemotherapy and radiation for those individuals. Rather we shift gears and recommend chemotherapy plus immune therapy, as we know that administering highly toxic therapies like radiation or taking an individual to surgery, with several weeks of surgical recovery and no treatment, the cons of doing that would outweigh the pros once the cancer has spread beyond a certain point, essentially to any other organs in the body.
Kristie L. Kahl: In addition to treatment, we've we also talked a lot about preventative measures to ensure that the disease doesn't spread. How does radiation play a role in say, for example, preventing metastases to the brain?
Wade T. Iams, MD: One of the unique dimensions of care for patients with small cell lung cancer is that when we're trying to cure individuals with small cell lung cancer, we do recommend preventative radiation to the brain. Now that comes into treatment after the individual has completed either their chemotherapy and radiation course, or their surgery followed by chemotherapy course. We recommend a brain MRI once they've completed the full treatment attempting to cure them. And as long as there is no cancer in the brain at that time, we do recommend preventative radiation to the brain. And that's radiation alone and in combination with chemotherapy at that point, just because the likelihood that small cell lung cancer goes to the brain is moderately high – high enough that in previous studies, it has been shown that cure rates can be increased when we do preventative radiation to the brain.
Now, I will say, preventative radiation to the brain adds side effects. And we are in an active time of evaluating that within the field. Particularly because our imaging technologies have improved, since the previous studies that showed that preventative radiation to the brain can increase cure rates, and that's being reevaluated with modern technology. So, time will tell whether we continue to find that preventative radiation to the brain increases cure rates and small cell lung cancer. But for now, we still recommend it.
Kristie L. Kahl: Are there any areas that are under evaluation in radiation or surgery to help improve treatment options for small cell lung cancer right now?
Wade T. Iams, MD: Yes, the biggest dimension under evaluation in radiation with small cell lung cancer is trying to add immune therapy after an individual completes chemotherapy and radiation, and even beginning immune therapy with chemotherapy and radiation. So, we are adding it with that chemotherapy and radiation approach. And then from the surgical aspect, one of the biggest discussions in the field is can we expand the group of patients who are eligible for surgery? And so that's under active investigation You know, might it be safe to think about doing surgery, if someone just has 1 small lymph node that's very close to that site of origin of the tumor? We don't know it's under investigation. But we're always trying to make sure that the recommendations for patients particularly when it comes down to attempting to cure those individuals, is supported by the best evidence that we're making the best decisions and recommendations for and with our patients.
