As many as 20% of the people who die from lung cancer in the United States every year do not smoke or use any other form of tobacco.
This translates to about 16,000 to 24,000 Americans every year. In fact, if lung cancer in non-smokers had its own separate category, it would rank among the top 10 fatal cancers in the United States.
It is true that staying away from tobacco is the most important thing any one can do to lower the risk of getting lung cancer. But there are also other risk factors that may contribute to lung cancer in non smokers.
Shamnuga Subbiah, M.D., medical oncologist at City of Hope, is here to educate the public about other risk factors for lung cancer and what changes can be made to lower the risk even further.
Selected Podcast
Lung Cancer in Non-Smokers
Featured Speaker:
Learn more about Shamnuga Subbiah, MD
Shanmuga Subbiah, MD
Shamnuga Subbiah, M.D., is a medical oncologist at City of Hope. He has previously practiced at the Wilshire Oncoology Medical Group and the Omaha VA Nebraska in Omaha, NE. He was also the Assistant Professor of Medicine in the Division of Oncology/Hematology at University of Nebraska Medical Center and Creighton University in Omaha, NE.Learn more about Shamnuga Subbiah, MD
Transcription:
Lung Cancer in Non-Smokers
Melanie Cole (Host): As many as 20% of the people who die from lung cancer in the United States every year do not smoke or use any other form of tobacco. It’s still true that staying away from tobacco is the most important thing any of us can do to lower our risk of getting lung cancer but there are also other risk factors that can contribute to lung cancer other than smoking. My guest today is Dr. Shanmuga Subbiah. He’s a medical oncologist at City of Hope. Welcome to the show, Dr. Subbiah. There’s a stigma around lung cancer, Dr. Subbiah, that if somebody has it or their loved one has it that people right away assume that they are a smoker. Speak about lung cancer in non-smokers.
Dr. Shanmuga Subbiah (Guest): We all know that lung cancer is associated with cigarette smoking and, in fact, if you look at lung cancer incidents among people, most of them are smokers and 85-90% of them are smokers. However, about 15-10% of all lung cancer patients are non-smokers and they are, like you mentioned, stigmatized and they are all lumped into one group as lung cancers only in smokers but 17,000 to 26,000 annual deaths from lung cancer is in never smokers. If you add that number and put it in the list of cancer-causing deaths, lung cancer in never smokers will be at the 7th cause right after pancreatic cancer. It’s a very important entity to be recognized and lots of work needs to be done in the future for this population.
Melanie: What are some of the other risk factors? If we take smoking out of the picture for a minute, what are some of the other risk factors? Does genetics play a role? Is it environmental? Pollutants? What else?
Dr. Subbiah: Definitely environmental and genetic factors are playing a role. It’s very unclear at this time to point out as to one thing causing the lung cancer in the never smokers. Secondhand smoke has been studied extensively and there are multiple studies supporting it and usually don’t support it. Secondhand smoke seems to be the number one thing that researchers have identified along with indoor pollution. I mean indoor pollution – radon. Radon is a product from radium. It’s found in the rock and soil. It tends to accumulate in our homes. People do check radon levels in the home and if you have a high incidence, that’s been associated with lung cancer. Use of chemicals from household products has been there but it’s not been well documented. Biological agents such as mold, as well, have been supported in some studies. Those are the main things that we know of. In Southeast Asia, particularly in China where there’s a high incidence of lung cancer in never smokers, cooking oils--vapor from cooking oils has been thought about as well. In a few studies, it has been shown to be positive and in some studies that hasn’t been shown. Those things, apart from occupational exposure, particularly to pesticides and grain elevator dust, wood dust, smoke, soot or exhaust has been also implicated in lung cancer in never smokers. When you mention genetic factors, we have found a particular gene that actually promotes sometimes lung cancer but a lot of studies are ongoing at this time. We feel that there must be some genetic factor but associated with an environmental factor that probably triggers to bring the lung cancer to the surface. That’s what we think is going on but no single genetic factor has been identified in an area of active research right now.
Melanie: Dr. Subbiah, when somebody does get diagnosed with lung cancer and, as I said at the beginning, there tends to be a stigma sometimes, do they feel like nobody believes them if they say, “No, I didn’t smoke. No, I’ve never smoked” and that people are like, “Yeah you’re just a closet smoker”. Have you heard that before?
Dr. Subbiah: I do. I’ve heard that before although I’ve heard that a lot when I started out practicing oncology I think awareness of lung cancer in non-smokers is being increasingly recognized by primary care providers and oncologists. From the medical provider side, the education is there but in the general population still there is a misconception that everybody who has lung cancer is a smoker. We haven’t educated the general population well about it yet. Still, one thing I always want to mention is the leading cause for lung cancer is still smokers and we need to target that population.
Melanie: For the non-smokers, what can we do to change our risk and lower our risk? Are there any lifestyle changes? If you have to work in one of these asbestos or mines or all of these kinds of cancer causing agents where you work, that’s maybe something that you can’t change. Are there things we can change?
Dr. Subbiah: No, just being aware of people’s secondhand smoke has been, again, like I mentioned, that has been the leading cause for it. So, trying to avoid being in spaces where people smoke but now there are laws in place which prevent people from smoking in public places, and that has helped a lot. Secondhand smoke and checking residential radon levels, particularly if you’re in an area that has high levels. That information can be obtained from your county website, so that should be helpful. There are lots of radon kits available and you can measure them and check them. Those are the things I probably would look at and people who are professionally or in populated exposures, they have to follow the precautions that are provided by their employer.
Melanie: Dr. Subbiah, is lung cancer different in smokers and non-smokers? Do you see a difference in the type of tumors or anything?
Dr. Subbiah: Yes. Certainly, we do see much different. You think it’s a totally different disease because in lung cancers of never smokers, we found that a type of lung cancer called adenocarcinoma is much more common than other types of lung cancers you see. Also, in adenocarcinomas, we found that there are a lot of genetic mutations. For instance, a mutation called EGFR mutation is only present in about 10% of all lung cancers in smokers. In Chinese studies, about 70% of them will have this mutation. Why do we need to know this mutation? Because we treat them differently. We have a pill and we use this pill and they seem to have wonderful responses to this pill. It’s not your usual chemotherapy that you use for most of our lung cancers. We have pills for what we call a “first generation pill” and there’s a “second generation pill” and there are “third generation pills” in studies. This has improved the outcome of these patients dramatically, I would say.
Melanie: The treatment does vary and do you see a difference in the outcome? Are they more likely to have a good recovery?
Dr. Subbiah: If you do have the mutation, then the pill will work for you. If you don’t have the mutation the pill doesn’t work very well for you. In that way, it definitely makes a difference. If you look at the overall outcome, it’s very unclear. There are two studies that we’ve known. One of the studies actually was done in southern California and what it found is that there was definitely improvement in survival outcomes for Japanese never smokers and in Caucasian never smokers compared to smokers with lung cancer. That study was just done looking at the local registry here in southern California. It definitely showed that there was an advantage for never smokers compared to smokers.
Melanie: Wow. Absolutely fascinating, Dr. Subbiah. What are you doing at City of Hope that really is exciting in advancement for lung cancer?
Dr. Subbiah: We have a number of clinical trials. Like I mentioned, there’s a first generation and a second generation drug approved. Right now, we are working on third generation drugs in the form of clinical trials. City of Hope is actively partnering with a number of pharmaceutical companies to bring these drugs early on to patients with this cancer which can have a worse outcome if not treated properly.
Melanie: Thank you so much for being with us. It’s great, great information and so important for people to hear. You’re listening to City of Hope Radio. For more information you can go to cityofhope.org. That’s cityofhope.org. This is Melanie Cole. Thanks so much for listening.
Lung Cancer in Non-Smokers
Melanie Cole (Host): As many as 20% of the people who die from lung cancer in the United States every year do not smoke or use any other form of tobacco. It’s still true that staying away from tobacco is the most important thing any of us can do to lower our risk of getting lung cancer but there are also other risk factors that can contribute to lung cancer other than smoking. My guest today is Dr. Shanmuga Subbiah. He’s a medical oncologist at City of Hope. Welcome to the show, Dr. Subbiah. There’s a stigma around lung cancer, Dr. Subbiah, that if somebody has it or their loved one has it that people right away assume that they are a smoker. Speak about lung cancer in non-smokers.
Dr. Shanmuga Subbiah (Guest): We all know that lung cancer is associated with cigarette smoking and, in fact, if you look at lung cancer incidents among people, most of them are smokers and 85-90% of them are smokers. However, about 15-10% of all lung cancer patients are non-smokers and they are, like you mentioned, stigmatized and they are all lumped into one group as lung cancers only in smokers but 17,000 to 26,000 annual deaths from lung cancer is in never smokers. If you add that number and put it in the list of cancer-causing deaths, lung cancer in never smokers will be at the 7th cause right after pancreatic cancer. It’s a very important entity to be recognized and lots of work needs to be done in the future for this population.
Melanie: What are some of the other risk factors? If we take smoking out of the picture for a minute, what are some of the other risk factors? Does genetics play a role? Is it environmental? Pollutants? What else?
Dr. Subbiah: Definitely environmental and genetic factors are playing a role. It’s very unclear at this time to point out as to one thing causing the lung cancer in the never smokers. Secondhand smoke has been studied extensively and there are multiple studies supporting it and usually don’t support it. Secondhand smoke seems to be the number one thing that researchers have identified along with indoor pollution. I mean indoor pollution – radon. Radon is a product from radium. It’s found in the rock and soil. It tends to accumulate in our homes. People do check radon levels in the home and if you have a high incidence, that’s been associated with lung cancer. Use of chemicals from household products has been there but it’s not been well documented. Biological agents such as mold, as well, have been supported in some studies. Those are the main things that we know of. In Southeast Asia, particularly in China where there’s a high incidence of lung cancer in never smokers, cooking oils--vapor from cooking oils has been thought about as well. In a few studies, it has been shown to be positive and in some studies that hasn’t been shown. Those things, apart from occupational exposure, particularly to pesticides and grain elevator dust, wood dust, smoke, soot or exhaust has been also implicated in lung cancer in never smokers. When you mention genetic factors, we have found a particular gene that actually promotes sometimes lung cancer but a lot of studies are ongoing at this time. We feel that there must be some genetic factor but associated with an environmental factor that probably triggers to bring the lung cancer to the surface. That’s what we think is going on but no single genetic factor has been identified in an area of active research right now.
Melanie: Dr. Subbiah, when somebody does get diagnosed with lung cancer and, as I said at the beginning, there tends to be a stigma sometimes, do they feel like nobody believes them if they say, “No, I didn’t smoke. No, I’ve never smoked” and that people are like, “Yeah you’re just a closet smoker”. Have you heard that before?
Dr. Subbiah: I do. I’ve heard that before although I’ve heard that a lot when I started out practicing oncology I think awareness of lung cancer in non-smokers is being increasingly recognized by primary care providers and oncologists. From the medical provider side, the education is there but in the general population still there is a misconception that everybody who has lung cancer is a smoker. We haven’t educated the general population well about it yet. Still, one thing I always want to mention is the leading cause for lung cancer is still smokers and we need to target that population.
Melanie: For the non-smokers, what can we do to change our risk and lower our risk? Are there any lifestyle changes? If you have to work in one of these asbestos or mines or all of these kinds of cancer causing agents where you work, that’s maybe something that you can’t change. Are there things we can change?
Dr. Subbiah: No, just being aware of people’s secondhand smoke has been, again, like I mentioned, that has been the leading cause for it. So, trying to avoid being in spaces where people smoke but now there are laws in place which prevent people from smoking in public places, and that has helped a lot. Secondhand smoke and checking residential radon levels, particularly if you’re in an area that has high levels. That information can be obtained from your county website, so that should be helpful. There are lots of radon kits available and you can measure them and check them. Those are the things I probably would look at and people who are professionally or in populated exposures, they have to follow the precautions that are provided by their employer.
Melanie: Dr. Subbiah, is lung cancer different in smokers and non-smokers? Do you see a difference in the type of tumors or anything?
Dr. Subbiah: Yes. Certainly, we do see much different. You think it’s a totally different disease because in lung cancers of never smokers, we found that a type of lung cancer called adenocarcinoma is much more common than other types of lung cancers you see. Also, in adenocarcinomas, we found that there are a lot of genetic mutations. For instance, a mutation called EGFR mutation is only present in about 10% of all lung cancers in smokers. In Chinese studies, about 70% of them will have this mutation. Why do we need to know this mutation? Because we treat them differently. We have a pill and we use this pill and they seem to have wonderful responses to this pill. It’s not your usual chemotherapy that you use for most of our lung cancers. We have pills for what we call a “first generation pill” and there’s a “second generation pill” and there are “third generation pills” in studies. This has improved the outcome of these patients dramatically, I would say.
Melanie: The treatment does vary and do you see a difference in the outcome? Are they more likely to have a good recovery?
Dr. Subbiah: If you do have the mutation, then the pill will work for you. If you don’t have the mutation the pill doesn’t work very well for you. In that way, it definitely makes a difference. If you look at the overall outcome, it’s very unclear. There are two studies that we’ve known. One of the studies actually was done in southern California and what it found is that there was definitely improvement in survival outcomes for Japanese never smokers and in Caucasian never smokers compared to smokers with lung cancer. That study was just done looking at the local registry here in southern California. It definitely showed that there was an advantage for never smokers compared to smokers.
Melanie: Wow. Absolutely fascinating, Dr. Subbiah. What are you doing at City of Hope that really is exciting in advancement for lung cancer?
Dr. Subbiah: We have a number of clinical trials. Like I mentioned, there’s a first generation and a second generation drug approved. Right now, we are working on third generation drugs in the form of clinical trials. City of Hope is actively partnering with a number of pharmaceutical companies to bring these drugs early on to patients with this cancer which can have a worse outcome if not treated properly.
Melanie: Thank you so much for being with us. It’s great, great information and so important for people to hear. You’re listening to City of Hope Radio. For more information you can go to cityofhope.org. That’s cityofhope.org. This is Melanie Cole. Thanks so much for listening.