Meta-Analysis and Systematic Review in Environmental Tobacco Smoke Risk of Female Lung Cancer by Research Type.

Xue Ni,Qiang Wang,Ning Xu

doi:10.3390/ijerph15071348

Abstract

More than 50% of women worldwide are exposed to Environmental Tobacco Smoke (ETS). The impact of ETS on lung cancer remains unclear. Cohort studies since the late 1990s have provided new evidence of female lung cancer risk due to ETS. The objective of this meta-analysis and systematic review was to analyze the association of ETS with female lung cancer risk from 1997 to 2017, organised based on research design. According to our applied inclusion and exclusion criteria, 41 published studies were included. The relative risk (RR) from the cohort studies or odds ratio (OR) from case-control studies were extracted to calculate the pooled risks based on the type of study. The summary risks of ETS were further explored with the modulators of ETS exposure sources and doses. The pooled risks of lung cancer in non-smoking women exposed to ETS were 1.35 (95% CI: 1.17–1.56), 1.17 (95% CI: 0.94–1.44), and 1.33 (95% CI: 1.17–1.51) for case-control studies, cohort studies, and both types of studies, respectively. The summary RR estimate of the cohort studies was not statistically significant, but the RR increased with increasing doses of ETS exposure (p trend < 0.05). Based on the results of this study, ETS might be an important risk factor of female lung cancer in non-smokers.

Highlights

Tobacco smoke has been proved to be the main factor influencing the risk of lung cancer.Except for carcinogens in the main stream of tobacco smoke, carcinogens such as benzo[a]pyrene,N 0 -nitrosonornicotine (NNN), and-1-(3-pyridyl)-1-butanone (NNK) are rich in sidestream smoke, called second-hand smoke [1]
The pollutants in residual tobacco smoke absorbed by clothing, hair, furnishings, and dust are labelled as third-hand smoke that contribute as a secondary source of indoor Environmental Tobacco Smoke (ETS) [2,3]
The references used in each study, the previous meta-analyses about the association of female lung cancer with ETS published publicly, and the reports about female lung cancer projects conducted in various countries were reviewed to select qualified literature

Summary

Introduction

Tobacco smoke has been proved to be the main factor influencing the risk of lung cancer.Except for carcinogens in the main stream of tobacco smoke, carcinogens such as benzo[a]pyrene,N 0 -nitrosonornicotine (NNN), and (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are rich in sidestream smoke, called second-hand smoke [1]. Tobacco smoke has been proved to be the main factor influencing the risk of lung cancer. Except for carcinogens in the main stream of tobacco smoke, carcinogens such as benzo[a]pyrene,. N 0 -nitrosonornicotine (NNN), and (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are rich in sidestream smoke, called second-hand smoke [1]. The pollutants in residual tobacco smoke absorbed by clothing, hair, furnishings, and dust are labelled as third-hand smoke that contribute as a secondary source of indoor Environmental Tobacco Smoke (ETS) [2,3]. Statistics about the global burden of disease related to ETS released by the World Health Organization (WHO) in 2011 showed that the global average proportion of children with at least one smoking parent, according to the definition from Global Youth Tobacco Survey, was estimated to be 41%, and the female adult. The association of ETS with the risk of lung cancer remains unclear

Methods

Results

Discussion

Conclusion