Abstract 5253: Dietary fiber intake and lung cancer risk: A pooled analysis of 1.44 million individuals in 10 cohorts

Abstract

Abstract Background: Dietary fiber has been shown to have various health benefits, including anti-inflammation. However, the role of dietary fiber on lung cancer risk has not been well characterized. In this pooled analysis of 10 prospective cohort studies from the US, Europe, and Asia, we evaluated the association between dietary fiber intake and risk of lung cancer and further, potential effect modifications by tobacco smoking, alcohol drinking, and demographic factors (e.g., sex and race/ethnicity). Methods: Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated within each cohort using Cox proportional hazard models with adjustment for major lung cancer risk factors. Risk estimates from each cohort were pooled using random-effects meta-analysis. To reduce potential reverse causation due to preclinical dietary changes, all analyses were conducted excluding the first two years of observation. Results: A total of 18,822 incident lung cancer cases were identified among 1,445,850 participants during mean follow-ups of 9.4 years. After adjustment for lung cancer risk factors (i.e., age, total energy, smoking status, smoking pack-years, gender, race/ethnicity, education, obesity status, diabetes, family history of lung cancer, alcohol consumption, physical activity level, menopausal status in women, and intake of saturated and polyunsaturated fat), dietary fiber intake was inversely associated with lung cancer risk (HR [95% CI] = 0.90 [0.83-0.99] for highest vs. lowest quintile and 0.93 [0.89-0.97] per 10g/day increase). Stratified analyses showed a significant inverse association in men (HRs [95% CIs] per 10g/day increase = 0.92 [0.85-1.00]), women (0.94 [0.90-0.99]), whites (0.92 [0.88-0.95]), smokers (0.92 [0.88-0.97]), and alcohol drinkers (0.89 [0.86-0.94]). However, no significant association was found in Blacks (1.05 [0.92-1.19]), Asians (0.99 [0.85-1.16]), never smokers (0.97 [0.88-1.07]), and never drinkers (0.99 [0.94-1.05]) (P interaction = 0.06 for sex, 0.004 for race, 0.17 for tobacco smoking, and <0.001 for alcohol drinking). Conclusion: Our findings suggest that a high-fiber diet was associated with a lower risk of lung cancer among whites, smokers, and alcohol drinkers. Further research is needed to determine if the association between dietary fiber intake and lung cancer risk reflects a causal relation. Citation Format: Jae Jeong Yang, Danxia Yu, Yong-Bing Xiang, William Blot, Kim Robien, Rashmi Sinha, Yikyung Park, Emily White, Yumie Takata, Mattias Johansson, Wei Zheng, Xiao-Ou Shu. Dietary fiber intake and lung cancer risk: A pooled analysis of 1.44 million individuals in 10 cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5253.