Not Just Smoking: Other Lifestyle Factors and Lung Cancer Risk

Dr. Bittoni, a research assistant professor at The Ohio State University Comprehensive Cancer Center, discusses lifestyle and environmental factors that can lead to lung cancer.

What is the reality of who is susceptible to receiving a lung cancer diagnosis?

It’s not always due to smoking. About 15% of people who are diagnosed with lung cancer are nonsmokers. That number has increased a bit over the years and is now closer to 16%. It could be genetic; it could be due to a family history, but sometimes people don’t even have a family history. It could be a mutation or environmental. For example, it could be radon—someone’s house could have been built on ground filled with radon and not know it—or other environmental causes.

What are some factors associated with lung cancer?

I’m involved in a collaboration with the University of Southern California, the Epidemiology of Young Lung Cancer study. We developed a 10-module risk factor survey that we tested. We did it ourselves because we wanted certain questions included. We developed the modules for different factors, including occupation, early life exposures, environmental, occupational, and so on. We are looking at people up to 50 years of age, because there has been a higher prevalence of younger people in their 20s being diagnosed with stage IV lung cancer.

Often, because they’re young, they don’t have the normal risk factors, and they’re probably more likely to be nonsmokers, nobody’s thinking it’s lung cancer. By the time they find out, it’s stage IV. A lot of these patients do have similar mutations and a similar genetic profile, which is good, because you can better target the treatment. We’re taking that genetic component, and we’re trying to match it to see if we can find any associated lifestyle factors. I presented the study at our World Lung Conference last year, and it’s ongoing. I’m currently looking at diet.

What have some of your studies shown?

We did find that the younger lung cancer participants had lower overall smoking rates and tended to have normal body mass index (BMI). They had a higher prevalence of antihistamine and oral contraceptive use and were more likely to have allergies during adolescence. We also found, as far as mutations, higher rates of EGFR. Patients with EGFR mutation had increased smoking, lower BMI, increased age, female gender, decreased oral contraceptive and antihistamine use, and fewer allergies compared with those with ALK mutations. We were only able to compare those two mutations, but we want to look at ROS1 and KRAS and plan to add them. We are seeing some associations with these mutations.

We’re doing this study to hopefully look at those lifestyle factors and even physical activity and diet. If we know there are associations between lung cancer risk and certain factors, we can try to target those factors. If somebody is at higher risk or is diagnosed, we can home in on that right away and try to prevent it or stop it from developing further.

What can be done to better educate patients and treat lung cancer?

Right now, the stigma for lung cancer is smoking. Almost without a doubt, if somebody says they have lung cancer or you tell somebody this person has lung cancer, the first question is, “Do they smoke?” That response implies a bit of a fault. “Well, they smoke, so they brought it on themselves.” But there are so many other factors, and not all people who smoke get lung cancer. About 10% to 15% of people who smoke get lung cancer, while 85% to 90% have smoked or smoke. It doesn’t mean that because you smoke, you’re going to lung cancer, but you’re at a higher risk. It’s just a stigma. We shouldn’t blame people for their disease. We have a lot of evidence on the impact of lifestyle factors, diet, and exercise.

It’s not just because if you’re healthier you eat a healthy diet or exercise. When you eat healthier and exercise more, it targets the cancer processes and stops some of them.

I didn’t mention the exercise study we’re doing. We don’t have results yet, but we’re looking at high-risk smokers who come in for lung screening; these are long-time smokers. We’re doing an exercise intervention with them, and we’re going to see if exercise changes some of their early markers, microbiome, and so on. We’re going to keep looking into those lifestyle factors.