Researchers from the University of Washington Schools of Public Health and Nursing found no significant associations between air pollution and breast cancer risk overall in a new study. But they did observe an increased risk of hormone receptor-positive breast cancer associated with higher exposure to nitrogen dioxide (NO2), a marker for traffic-related air pollution.

The study was published in the December issue of Cancer Epidemiology, Biomarkers & Prevention. Researchers used data from more than 47,000 women in the NIH-funded Sisters Study and also estimated air pollution concentration outside of residences.

Researchers reported no association between invasive breast cancer overall and ambient fine-particulate matter (PM2.5 and PM10) or NO2. However, NO2 was associated with a 1.10-fold increased risk of ER+/PR+ breast cancer.

Researchers said the results need to be replicated before firm conclusions can be drawn about hormone receptor-positive breast cancer and traffic-related air pollution. Collaborating institutions included the Fred Hutchinson Cancer Research Center, the University of Bergen, Norway, and the National Institute of Environmental Health Sciences.

Link: http://cebp.aacrjournals.org/content/24/12/1907.abstract