Abstract 595: Circulating levels of coenzyme Q10 and lung cancer risk
Authors: Shidal Chris , Yoon Hyung-Suk , Zheng Wei , Wu Jie , Franke Adrian A. , Blot William J. , Shu Xiao-Ou , Cai Qiuyin 
Published: August 2019

Abstract
Background: Coenzyme Q10 (CoQ10) is an ubiquitous molecule in living organisms that serves as a cofactor in energy production via the electron-transport chain (ETC). Research has previously shown that deficiencies in CoQ10 can result in a variety of detrimental outcomes including cardiovascular disease and neurological disorders. More recently, epidemiological studies have reported low CoQ10 levels being associated with increased risk of breast, ovarian, and skin cancers. However, studies exploring the link between CoQ10 and lung cancer risk are largely lacking.
Methods: A nested case-control study including 201 lung cancer cases and 395 matched controls from the Southern Community Cohort Study (SCCS) was conducted. Plasma CoQ10 levels were measured using high-performance liquid chromatography (HPLC). A conditional logistic regression model was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the association between plasma CoQ10 concentrations and lung cancer risk. CoQ10 level was categorized by tertile distribution among controls.
Results: Plasma CoQ10 concentration was inversely associated with risk of lung cancer. Compared to the first tertile, the ORs (95% CI) were 0.82 (0.52-1.31) and 0.57 (0.34-0.96) for the second and third tertile, respectively, (P for trend=0.038), after adjusting for age, smoking status and pack-years of smoking. Additional adjustment for alcohol consumption, education, income, history of COPD and BMI slightly attenuated the association (OR=0.60, 95% CI=0.34-1.08, comparing third to first tertile). No notable difference was found between African Americans and European Americans. Stratified analysis identified a significant association between CoQ10 and lung cancer in current smokers (OR=0.47, 95% CI=0.26-0.87, third vs. first tertile), but not in former/never smokers (OR=0.84, 95% CI=0.35-2.03). The significant associations between CoQ10 and lung cancer risk were more evident in cases who were diagnosed within one year of blood draw (OR=0.17, 95% CI=0.04-0.73, third vs. first tertile, P for trend=0.023) than in cases diagnosed after one year following blood draw (OR=0.72, 95% CI=0.36-1.41).
Conclusions: Findings from this study suggest that Coenzyme Q10 may be a potential marker for lung cancer, although the stronger effect shortly after diagnosis indicates the association may be related to dietary or other changes associated with the cancer diagnosis rather than CoQ10 being a causal risk biomarker. Further studies exploring the link between CoQ10 and lung cancer risk are necessary to better understand the role of CoQ10 in lung carcinogenesis.
Citation Format: Chris Shidal, Hyung-Suk Yoon, Wei Zheng, Jie Wu, Adrian A. Franke, William J. Blot, Xiao-Ou Shu, Qiuyin Cai. Circulating levels of coenzyme Q10 and lung cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 595.