Exposure to environmental tobacco smoke in childhood and incidence of cancer in adulthood in never smokers in the European prospective investigation into cancer and nutrition

Abstract

The association between childhood environmental tobacco smoke (ETS) exposure and adult cancer risk is controversial; we examined this relationship in never smokers within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Over an average of 10 years, 8,372 cases of cancer were diagnosed in 112,430 never smokers in EPIC. Childhood ETS was self-reported by participants at baseline, along with other lifestyle factors. Hazard ratios (HR) for ETS exposure in childhood and their 95% confidence intervals (CI) were estimated by Cox proportional hazards models stratified by age, sex, and study center and adjusted for education, alcohol drinking, body mass index, physical activity, non-alcoholic energy intake, fruit and vegetable intake, and adulthood ETS exposure. Models were further adjusted for reproductive factors for female cancers, for meat intake for digestive system cancers, and for diabetes status for pancreatic cancer. No association was observed between childhood 123Cancer Causes Control (2011) 22:487-494 DOI 10.1007 ETS exposure and overall cancer risks (HR = 0.97, 95% CI = 0.92-1.02), and for selected sites. The only exception was pancreatic cancer, as previously reported by Vrieling et al., among those who had been exposed daily in childhood (overall HR = 2.09, 95% CI = 1.14-3.84). In conclusion, childhood ETS exposure might not be a major risk factor for common cancers in adulthood.

Environmental tobacco smoke and the risk of pancreatic cancer among non-smokers: a meta-analysis

“…One of the 9 selected articles included two independent studies19 so there were a total of 10 studies considered, including 6 prospective cohort studies,12 13 19–21 3 retrospective case–control studies22–24 and 1 prospective case–cohort study 25. (table 1) Four of the studies were conducted in the USA, three in western European countries, one in Canada, one in Japan and one in Egypt (the only one in a middle-income or low-income country).…”

“…In total, four prospective studies12 13 20 25 and two retrospective studies23 24 investigated the association between childhood ETS exposure and the risk of pancreatic cancer. As two prospective studies12 13 were both conducted within the European Prospective Investigation into Cancer and Nutrition cohort, only one of them12 was included in the analysis (further details are provided in the Methods section).…”

“…As two prospective studies12 13 were both conducted within the European Prospective Investigation into Cancer and Nutrition cohort, only one of them12 was included in the analysis (further details are provided in the Methods section). After the exclusion, RR estimates ranged from 0.90 (95% CI 0.54 to 1.50; Heinen et al 25) to 2.09 (95% CI 1.14 to 3.84; Chuang et al 12). Of these, only the RR estimate from the study by Chuang et al 12 reached statistical significance.…”

“…Two included studies examined the relationship between childhood ETS exposure and risk of pancreatic cancer within the European Prospective Investigation into Cancer and Nutrition cohort 12 13. We chose to include only the study of Chuang et al 12 when summarising the evidence for childhood ETS, because this study was conducted with a larger sample size and adjusted for greater number of potential confounders.…”

“…We chose to include only the study of Chuang et al 12 when summarising the evidence for childhood ETS, because this study was conducted with a larger sample size and adjusted for greater number of potential confounders.…”