PM2.5 exposure ups risk of lung adenocarcinoma in women

Residential exposure to fine particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) appear to elevate the risk of lung adenocarcinoma in women, suggests a Taiwan study.

A total of 21,301 female lung cancer patients had been diagnosed between 2012 and 2017. The investigators matched each patient by age, sex, and calendar year to four controls randomly selected from the general population. They estimated each participant’s exposures to PM_2.5 and nitrogen dioxide (NO₂) according to the residential changes from 2000, allowing a latent period of 5 years.

The investigators adopted self-reported smoking statuses for the patients and estimated those of controls using annual surveys in each residential county. Finally, they examined the associations between PM_2.5 and NO₂ exposures and incident lung cancer cases using multiple logistic regression analyses.

After adjusting for smoking, residence, and comorbidities, participants in the third (30.5–35.1 μg/m³), fourth (35.1–39.3 μg/m³) and fifth PM_2.5 exposure quintiles (39.3–48.1 μg/m³) had odds ratios of 1.10 (95 percent confidence interval [CI], 1.04‒1.16), 1.12 (95 percent CI, 1.06‒1.19), and 1.10 (95 percent CI, 1.04‒1.16), respectively, compared with those in the first quintile.

A dose-response relationship (p=0.004) was observed. Notably, these associations persisted with a 10-year latency and were not detected for small-cell and squamous cell carcinoma after controlling for smoking. Finally, no similar effect was seen for NO₂ exposure.

“The prevalence of smoking among women in Taiwan is <5 percent, but the incidence of lung cancer remains high,” the investigators said.