Amanda Wilde (Host): There is a growing number of people diagnosed with lung cancer despite being lifetime non-smokers. We'll explore the circumstances of non-smokers at risk for lung cancer, next with thoracic surgeon, Dr. Brian Cohen. This is WakeMed Voices brought to you by WakeMed Health and Hospitals in Raleigh, North Carolina.

I'm Amanda Wilde. Dr. Cohen, thank you so much for being here.

Brian Cohen, MD: Absolutely. Thank you so much for having me.

Host: Dr. Cohen, can you explain why non-smokers might develop lung cancer?

Brian Cohen, MD: Yeah, absolutely. So the vast majority of lung cancers do occur in current or former smokers. That's upwards of 85% of cases. That said, there is still a large subset of lung cancer patients who are never smokers, and that slice of patients has been increasing. It's mostly on account of smoking rates decreasing, but it's an important and growing category of patients nonetheless. There are some risk factors we know about and can quantify, secondhand smoke being the biggest risk factor, but also specific environmental exposures. Indoor air pollution that's being in closed spaces with stoves or smokers. Some specific occupational exposures like radon or asbestos.

And then there's a whole subset of genetic factors that would predispose someone to cancer. These are cancers we're seeing increasingly in non-smokers, predominantly women and predominantly in Asian populations. And they carry a specific gene mutation within the cancer cells.

So unfortunately, a lot of those are demographic risk factors, not actions that we can pinpoint that helps say this person should stop doing this in order to decrease their risk of cancer. But we do see those genetic changes in a lot of non-smokers.

Host: So the risk factors causing lung cancer in non-smokers are really no different from those who are smokers. As you said the incidences of smoking regularly are going down, so that statistics go up for non-smokers. But also it sounds like there are more of those environmental factors and now we see there's a genetic component as well.

Brian Cohen, MD: Yep, that's right. And it's a good thing smoking rates are going down, but it does lend more importance to these environmental factors and changes the makeup of who we see a little bit with who's getting lung cancer.

Host: So is there a difference in the kind of lung cancer non-smokers develop versus smokers?

Brian Cohen, MD: Yes, for those specific genetic changes, for the ones with those genetic mutations, they do behave differently and they're a unique subset of lung cancers, cancers that pop up on their own without those specific genetic mutations, may be because of environmental factors, those behave more like cancer in smokers.

Host: Is there a difference in the aggressiveness of lung cancer in the non-smoking population that you see increasing?

Brian Cohen, MD: There are important differences in the treatment options, I would say is an important way that we think about it. There are specific medications that can target those lung cancers with this specific genetic mutations and opens up a huge avenue of treatment for these patients.

Host: So you're talking genetic predisposition and also are there gender disparities in non-smokers developing lung cancer?

Brian Cohen, MD: There are. So non-smokers and I keep referring to these specific genetic mutations. I'm, referring specifically to EGFR mutations or alk rearrangements are two of the major ones that we're testing for and see, and in those patients we do see female predominance.

Host: And we don't know why that is, I assume,

Brian Cohen, MD: I wish we had better information or more information. We don't know why that is.

Host: But it's something to be aware of, right?

Brian Cohen, MD: It's something to be aware of when we see a patient who's a never smoker, who is a woman, and specifically in an Asian population, or from an Asian population, our radars go up for these genetic modifications, and again, it changes how we can treat these patients.There are some great medications available that target those specific mutations.

Host: Dr. Cohen, are there screening tools available that show that you have lung cancer or that you're at a higher risk for lung cancer?

Brian Cohen, MD: There's an extremely important screening program that we have. It is targeted for higher risk patients. So that's the smoking population. These genetic changes and these other lower risk populations or populations we don't usually think of, of having lung cancer, there's not a screening program in place.

Host: So what steps should a person take if they are concerned about possible lung cancer?

Brian Cohen, MD: Always having a conversation with your doctor is important. We are speaking about a very small subset of patients when you don't have specific risk factors, especially a smoking history. There is not a test that we generally offer as a screening tool. That said, if you have a family history or specific environmental exposures or something you're worried about, then that's absolutely a good conversation to have with your doctor to see if there's any other imaging that should be available.

Host: I don't know that we talked about this earlier, but do symptoms exist that are different in the non-smoking population, symptoms of lung cancer, or is it one of those situations where you don't really find the symptoms until they're more progressed?

Brian Cohen, MD: Yeah, the earlier stage lung cancers would generally not have symptoms when it's early. The most common symptom for any cancer, any lung cancer would be a cough, sometimes wheezing, sometimes coughing up blood. Later cancers would present with weight loss or fatigue, but that is not different between smokers or non-smokers.

Host: Is there anything we can do on the preventive side to lower risk?

Brian Cohen, MD: Absolutely to the point of, well we talked a little bit about smoking, but smoking cessation programs are extremely important. And that is the biggest risk factor and the biggest modifiable risk factor that we can affect. So stopping smoking and then decreasing your environmental exposures.

So that's your exposure to secondhand smoke. If you're in an enclosed kitchen with a lot of smoke or ovens, or known pollutants. Those are also extremely important environmental factors to take into account in order to decrease risk.

Host: Dr. Cohen, thank you for sharing your expertise on lung cancer and this vital information today.

Brian Cohen, MD: Absolutely. Thank you again for having me.

Host: Dr. Brian Cohen is a thoracic surgeon at WakeMed Cardiovascular and Thoracic Surgery. To learn more about WakeMed lung and chest services, please visit wakemed.org. I'm Amanda Wilde with WakeMed Voices brought to you by WakeMed Health and Hospitals in Raleigh, North Carolina.