Particulate Matter Air Pollution Contributes to Increased Risk of Lung Cancer in Europe
Ambient air pollution has been associated with lung cancer risk. In a study reported in Lancet Oncology by Ole Raaschou-Nielsen, PhD, of the Danish Cancer Society Research Center, and colleagues, lung cancer incidence in European countries was prospectively assessed according to several measures of air pollution exposure. The study showed that particulate matter air pollution contributes to risk of lung cancer, particularly adenocarcinoma.
Study Details
The study prospectively analyzed data from the European Study of Cohorts for Air Pollution Effects, including data from 17 cohort studies based in nine European countries. Baseline addresses were geocoded and air pollution was assessed by land-use regression models for particulate matter with diameter of less than 10 μm, less than 2.5 μm, and between 2.5 and 10 μm, soot, nitrogen oxides, and two road traffic categories.
The 312,944 cohort members contributed 4,013,131 person-years at risk. During a mean follow-up of 12.8 years, 2,095 incident lung cancer cases were diagnosed. Meta-analyses were performed using various models, including a model (incorporating other models) adjusting for age, sex, calendar time (year of enrollment), smoking status, smoking intensity, square of smoking intensity, smoking duration, time since quitting smoking, environmental tobacco smoke, occupation, fruit intake, marital status, education levels, employment status, and area-level socioeconomic status.
Significantly Increased Risk of All Lung Cancers, Adenocarcinomas
Meta-analysis including all participants showed a statistically significant association between risk for lung cancer and particulate matter < 10 µm with a hazard ratio (HR) of 1.22 (95% confidence interval [CI] = 1.03–1.45) per 10 μg/m3. For particulate matter < 2.5 µm the hazard ratio was 1.18 (95% CI 0.96–1.46) per 5 μg/m3. The same increments of particulate matter < 10 µm and particulate matter < 2.5 µm were associated with significantly increased hazard ratios for adenocarcinomas of the lung of 1.51 (95% CI = 1.10–2.08) and 1.55 (95% CI = 1.05–2.29), respectively. Respective hazard ratios for squamous cell carcinoma were 0.84 (95% CI = 0.50–1.40) and 1.46 (95% CI = 0.43–4.90).
An increase in road traffic of 4,000 vehicle-km per day within 100 m of the residence was associated with a hazard ratio for lung cancer of 1.09 (95% CI = 0.99–1.21). There was no association between lung cancer and nitrogen oxides concentration (HR = 1.01, 95% CI = 0.95–1.07, per 20 μg/m3) or traffic intensity on the nearest street (HR = 1.00, 95% CI = 0.97–1.04, per 5,000 vehicles per day).
Meta-analysis using the same model but restricted to participants who did not change residence during follow-up showed hazard ratios for particulate matter < 10 µm and particulate matter < 2.5 µm of 1.48 (95% CI = 1.16–1.88) and 1.33 (95% CI = 0.98–180) for all lung cancers, 2.27 (95% CI = 1.32–3.91) and 1.65 (95% CI = 0.93–2.95) for adenocarcinomas, and 0.64 (95% CI = 0.28–1.48) and 0.65 (95% CI = 0.16–2.57) for squamous cell carcinomas.
The investigators concluded, “This very large multicentre study shows an association between exposure to particulate matter air pollution and the incidence of lung cancer, in particular adenocarcinoma, in Europe, adding substantially to the weight of the epidemiological evidence.”
Funding was provided by the European Community’s Seventh Framework Programme.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
