Dr. Chen Discusses the Link Between PM2.5 Exposure, Lung Cancer in Women Who Never Smoked

Yixian Chen, PhD, of the British Columbia Cancer Research Institute, joined Lung Cancers Today at the 2024 IASLC World Conference on Lung Cancer to discuss her research on the link between exposure to particulate matter less than 2.5 micrometers in diameter (PM_2.5) and lung cancer in people who have never smoked.

Dr. Chen explained that it was important to conduct the study because air pollution is a contributor to the incidence of lung cancer, particularly in women. However, questions remain about the timing and duration of PM_2.5 exposures as they relate to the development of lung cancer and the risk of lung cancer.

To address the knowledge gap, Dr. Chen and colleagues “compared the effect of short- and long-term exposure to PM_2.5 with EGFR mutation in lung cancer patients who have never smoked,” she explained.

The researchers collected data from patient-completed questionnaires including patient residential history from their birth to their lung cancer diagnosis. They then geocoded each residential address and analyzed high-resolution concentration estimates of PM_2.5 exposure from satellite data, chemical transport models, and ground measurements within areas corresponding to the time the individual lived at each address.

The analysis included more than 250 patients with newly diagnosed lung cancer who had never smoked and had a known EGFR mutation status. The study showed significant associations between the EGFR mutation and the cancer stage, with a significantly higher proportion of patients with EGFR mutations being diagnosed at stage IV, compared to those without.

Dr. Chen and colleagues also found differences in the cumulative 3-year PM_2.5 exposure before diagnosis in women who never smoked and had EGFR mutations compared to those without. This trend continued when they examined the cumulative 5-year-exposure before diagnosis, with a higher exposure level observed in those with EGFR mutations.

However, these associations were not found in men who had never smoked, and long-term exposures over 10-20 years were not linked with EGFR mutation status in men or in women.

“This is a very preliminary result, and we want to verify it with a larger sample size, but it seems like the risk of EGFR mutations in lung cancer patients is associated with short-term pollution [exposure],” Dr. Chen said.

Based on these results, Dr. Chen explained the next steps that could be taken within this line of research, explain that further studies will be needed to confirm if PM_2.5 measurement over three to five years could be adequate for lung cancer risk assessment.

“We would like to expand our study sample, recruit more participants, and if we can recruit participants from other geographical regions, that would be even better,” Dr. Chen said. “Also, we want to add more covariates such as a different air pollution indicators, and we want to improve how we measure exposure.”