RESEARCH ARTICLE
Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A CaseControl Study in China Bin Li1,2, Lian Wang1, Min-Shan Lu1, Xiong-Fei Mo3, Fang-Yu Lin4, Suzanne C. Ho5*, Cai-Xia Zhang1*
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1 Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China, 2 Epidemiology Research Unit, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 3 Department of Vascular Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 4 Nursing Department, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 5 Division of Epidemiology, The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China * [email protected] (C-XZ); [email protected] (SCH)
OPEN ACCESS Citation: Li B, Wang L, Lu M-S, Mo X-F, Lin F-Y, Ho SC, et al. (2015) Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A CaseControl Study in China. PLoS ONE 10(4): e0125894. doi:10.1371/journal.pone.0125894 Academic Editor: Suminori Akiba, Kagoshima University Graduate School of Medical and Dental Sciences, JAPAN Received: October 31, 2014 Accepted: March 23, 2015 Published: April 27, 2015 Copyright: © 2015 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: This study was supported by the National Natural Science Foundation of China (no. 81102188), the New Teachers’ Fund for Doctor Stations, Ministry of Education of China (no. 20100171120057). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.
Abstract Background The role of passive smoking on breast cancer risk was unclear. This study aimed to evaluate the association between passive smoking and breast cancer risk among Chinese women.
Methods/Principal Findings A hospital-based case-control study, including 877 breast cancer cases and 890 controls, frequency-matched by age and residence, was conducted. A structured questionnaire was used to collect information on passive smoking history through face-to-face interview by trained interviewers. Unconditional logistic regression models were used to estimate the association between passive smoking and breast cancer risk. A positive association between any passive smoking exposure and breast cancer risk was observed. Compared with women who were never exposed to passive smoking, women who were ever exposed had a higher breast cancer risk, with the adjusted odds ratio (OR) and 95% confidence interval (CI) of 1.35 (1.11-1.65). Similar result was found on home passive smoking exposure and breast cancer risk, but not on workplace passive smoking exposure. Women who were ever exposed to tobacco smoke at home had a higher risk of breast cancer compared with never exposed women, with the adjusted OR (95% CI) of 1.30 (1.05-1.61). Home passive smoking exposure showed significant dose-response relationships with breast cancer risk in smoker-years, cigarettes/day and total pack-years (Ptrend=0.003, 0.006 and 0.009, respectively). An increased total smoker-years of any passive exposure significantly elevated the risk of breast cancer (Ptrend
Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A CaseControl Study in China Bin Li1,2, Lian Wang1, Min-Shan Lu1, Xiong-Fei Mo3, Fang-Yu Lin4, Suzanne C. Ho5*, Cai-Xia Zhang1*
a11111
1 Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China, 2 Epidemiology Research Unit, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 3 Department of Vascular Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 4 Nursing Department, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China, 5 Division of Epidemiology, The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China * [email protected] (C-XZ); [email protected] (SCH)
OPEN ACCESS Citation: Li B, Wang L, Lu M-S, Mo X-F, Lin F-Y, Ho SC, et al. (2015) Passive Smoking and Breast Cancer Risk among Non-Smoking Women: A CaseControl Study in China. PLoS ONE 10(4): e0125894. doi:10.1371/journal.pone.0125894 Academic Editor: Suminori Akiba, Kagoshima University Graduate School of Medical and Dental Sciences, JAPAN Received: October 31, 2014 Accepted: March 23, 2015 Published: April 27, 2015 Copyright: © 2015 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: This study was supported by the National Natural Science Foundation of China (no. 81102188), the New Teachers’ Fund for Doctor Stations, Ministry of Education of China (no. 20100171120057). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist.
Abstract Background The role of passive smoking on breast cancer risk was unclear. This study aimed to evaluate the association between passive smoking and breast cancer risk among Chinese women.
Methods/Principal Findings A hospital-based case-control study, including 877 breast cancer cases and 890 controls, frequency-matched by age and residence, was conducted. A structured questionnaire was used to collect information on passive smoking history through face-to-face interview by trained interviewers. Unconditional logistic regression models were used to estimate the association between passive smoking and breast cancer risk. A positive association between any passive smoking exposure and breast cancer risk was observed. Compared with women who were never exposed to passive smoking, women who were ever exposed had a higher breast cancer risk, with the adjusted odds ratio (OR) and 95% confidence interval (CI) of 1.35 (1.11-1.65). Similar result was found on home passive smoking exposure and breast cancer risk, but not on workplace passive smoking exposure. Women who were ever exposed to tobacco smoke at home had a higher risk of breast cancer compared with never exposed women, with the adjusted OR (95% CI) of 1.30 (1.05-1.61). Home passive smoking exposure showed significant dose-response relationships with breast cancer risk in smoker-years, cigarettes/day and total pack-years (Ptrend=0.003, 0.006 and 0.009, respectively). An increased total smoker-years of any passive exposure significantly elevated the risk of breast cancer (Ptrend
