Long-term Exposure to Traffic-related Air Pollution and Cancer Risk Among Survivors of Myocardial Infarction: a 20-year Follow-up Study - The 63rd Annual Conference of the Israel Heart Society in association with the Israel Society of Cardiothoracic Surgery 12-13 April 2016, David Intercontinental Hotel, Tel-Aviv, Israel

Gali Cohen ¹ Ilan Levy ² David M. Broday ² Jeremy D. Kark ³ Noam Levin ⁴ Yuval , ² David M. Steinberg ⁵ Yariv Gerber ¹

¹Dept. of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv
²Technion Center of Excellence in Exposure Science and Environmental Health, Technion Israel Institute of Technology, Haifa
³Epidemiology Unit, Braun School of Public Health and Community Medicine, Hebrew University and Hadassah Medical Organization, Jerusalem
⁴Dept. of Geography, Hebrew University of Jerusalem, Jerusalem
⁵Dept. of Statistics and Operations Research, School of Mathematical Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv

Background: Recent evidence suggests an association between long-term exposure to traffic-related air pollution and risk of cancer, particularly lung cancer, and recently bladder, kidney and prostate cancers. Higher cancer incidence rates in survivors of myocardial infarction (MI) compared with the general population are increasingly recognized. We examined the association between residential exposure to nitrogen oxides (NO_x), a proxy for traffic-sourced air pollution, and cancer incidence and mortality in a cohort of MI patients.

Methods: Patients aged ≤65 years admitted to hospital in central Israel with first MI in 1992-1993 were followed through 2013 for cancer via the National Cancer Registry. Data on socio-demographic and cancer risk factors were obtained, including time-varying information on smoking. Using land-use regression models, annual averages of NO_x during follow-up were estimated individually, according to geocoded home addresses recorded at baseline and confirmed after five years. Cox models were used to study the relationships between NO_x and cancer outcomes, treating NO_x and smoking as time-dependent variables.

Results: During 21684 person years (mean (SD), 15.6 (6.9)), 262 new cases of cancer were diagnosed and 107 cancer deaths were identified among 1393 cancer-free patients at baseline (mean age, 54 years; 81% men). Mean NO_x exposure during follow-up was 24 ppb (range 9-84). In fully adjusted models, a 10-ppb increase in mean NO_x exposure was positively associated with all cancer incidence (hazard ratio (HR)=1.06; 95% confidence interval (CI): 0.96, 1.18) and mortality (HR=1.07; 95% CI: 0.92, 1.24). Restricted to lung, bladder, kidney and prostate cancer incidence, the association was strengthened (HR=1.16; 95% CI: 1.00, 1.33). HRs were further elevated when excluding persistent heavy smokers (Table).

Conclusions: Chronic residential exposure to NO_x may constitute an environmental risk factor for cancer incidence and mortality among MI survivors. Variation in the strength of association between specific cancers needs to be further explored.

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