The effect of atmospheric particulate matter on survival of breast cancer among US females

• Published in: Breast cancer research and treatment Vol. 139; no. 1; pp. 217 - 226
• Main Authors: Hu, Hui, Dailey, Amy B., Kan, Haidong, Xu, Xiaohui
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2013; Springer; Springer Nature B.V
• Subjects: Adult; Aged; Air pollution; Air Pollution - adverse effects; Airborne particulates; Analysis; Biological and medical sciences; Breast cancer; Breast Neoplasms - mortality; Cancer research; Cancer therapies; Environmental Exposure - adverse effects; Epidemiology; Female; Gynecology. Andrology. Obstetrics; Humans; Kaplan-Meier Estimate; Mammary gland diseases; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Oncology; Particulate Matter - adverse effects; Proportional Hazards Models; SEER Program; Tumors; United States - epidemiology; United States; North America; America; USA, California; Air pollution; Breast cancer; Cancer survival; Particulate matter; Human; Breast disease; Malignant tumor; Survival; Mammary gland diseases; Female; Woman; Public health; Cancer
• ISSN: 0167-6806; 1573-7217
• DOI: 10.1007/s10549-013-2527-9

Short-term effects of ambient particulate matter (PM) on cardiopulmonary morbidity and mortality have been consistently documented. However, no study has investigated its long-term effects on breast cancer survival. We selected all female breast cancer cases ( n  = 255,128) available in the California Surveillance Epidemiology and End Results cancer data. These cases were linked to 1999–2009 California county-level PM daily monitoring data. We examined the effect of PM on breast cancer survival. Results from Kaplan–Meier survival analysis show that female breast cancer cases living in areas with higher levels of PM 10 and PM 2.5 had a significant shorter survival than those living in areas with lower exposures ( p  < 0.0001). The results from marginal cox proportional hazards models suggest that exposure to higher PM 10 (HR 1.13, 95 % CI 1.02–1.25, per 10 μg/m 3 ) or PM 2.5 (HR 1.86, 95 % CI 1.12–3.10, per 5 μg/m 3 ) was significantly associated with early mortality among female breast cancer cases after adjusting for individual-level covariates such as demographic factors, cancer stage and year diagnosed, and county-level covariates such as socioeconomic status and accessibility to medical resources. Interactions between cancer stage and PM were also observed; the effect of PM on survival was more pronounced among individuals diagnosed with early stage cancers. This study suggests that exposure to high levels of PM may have deleterious effects on the length of survival from breast cancer, particularly among women diagnosed with early stage cancers. The findings from this study warrant further investigation.