ASPO Abstracts
Outdoor Air Pollution Exposure and Uterine Cancer Incidence in the U.S.-Wide Sister Study
Category: Molecular Epidemiology & Environment
Conference Year: 2023
Abstract Body:
Purpose: Outdoor air pollution is an established lung carcinogen, but little is known about how it is related to the risk of other cancer types. In addition to carcinogens, air pollution includes endocrine disrupting compounds which may be particularly relevant for hormone-sensitive outcomes, such as uterine cancer. We investigated the association between uterine cancer incidence and residential exposure to particulate matter with an aerodynamic diameter <2.5 µg/m3 (PM2.5) and nitrogen dioxide (NO2). Methods: We included 34,650 participants in the U.S-wide Sister Study cohort with no prior history of uterine cancer and an intact uterus at baseline (2003-2009). Annual outdoor air pollution concentrations were estimated at each participant's residence using a validated spatio-temporal model. Cox proportional hazards models estimated adjusted hazard ratios (HR) for uterine cancer associated with an interquartile range (IQR) increase in air pollutant levels and increasing exposure quartiles relative to the lowest. Models were adjusted for age, race/ethnicity, level of attained education, neighborhood deprivation measured using the Area Deprivation Index (a census-block group level score of socioeconomic indicators), census region, smoking status, age at menarche, body mass index, menopausal status, hormone therapy use and were mutually adjusted for the other air pollutant. Results: Over an average of 11.9 years of follow-up, there were 376 incident uterine cancer cases diagnosed in the cohort. An IQR increase in NO2 (5.9 ppb) was associated with an elevated rate of uterine cancer (HR=1.09, 95% CI: 0.94-1.28), with the highest rate observed among women in the 4th quartile compared to the lowest quartile although confidence intervals were wide (HR=1.14, 95% CI: 0.81-1.60). However, no increase in the rate of uterine cancer was observed per IQR increase in PM2.5 (3.3 µg/m3; HR=0.93, 95% CI: 0.75-1.14). Conclusions: Higher residential exposure to NO2, an indicator of traffic-related air pollution, may be related to a higher incidence of uterine cancer in this large prospective study of U.S. women.
Keywords: air pollution, uterine cancer, nitrogen dioxide