Statins dose-dependently exert a significant chemopreventive effect on colon cancer in patients with chronic obstructive pulmonary disease: A population-based cohort study

// Ju-Chi Liu 1, 4, * , Wen-Rui Hao 1, * , Yi-Ping Hsu 1 , Li-Chin Sung 1, 4 , Pai-Feng Kao 1, 4 , Chao-Feng Lin 1 , Alexander T.H. Wu 6 , Kevin Sheng-Po Yuan 7 , Szu-Yuan Wu 2, 3, 4, 5 1 Division of Cardiovascular Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei, Taiwan 2 Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan 3 Department of Radiation Oncology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan 4 Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 5 Department of Biotechnology, Hungkuang University, Taichung, Taiwan 6 Ph.D. Program for Translational Medicine, Taipei Medical University, Taipei, Taiwan 7 Department of Otorhinolaryngology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan * These authors have contributed equally to this work Correspondence to: Szu-Yuan Wu, email: szuyuanwu5399@gmail.com Keywords: statins, chronic obstructive pulmonary disease, colon cancer Received: March 22, 2016 Accepted: June 27, 2016 Published: August 12, 2016 ABSTRACT Purpose: We evaluated the chemopreventive effect of statins on colon cancer in patients with chronic obstructive pulmonary disease (COPD) and identified the statin exerting the strongest chemopreventive effect. Methods: Using the National Health Insurance Research Database, we identified patients who received a COPD diagnosis in Taiwan between January 1, 2001, and December 31, 2012, and included them in the study cohort. Each patient was followed to assess the colon cancer risk and protective factors. A propensity score was derived using a logistic regression model to estimate the effect of statins by accounting for covariates predicted during the intervention (statins). To examine the dose–response relationship, we categorized statin doses into four groups in each cohort [ 365 cumulative defined daily dose]. Results: Compared with the statin nonusers, the adjusted hazard ratio (aHR) for colon cancer decreased in the statin users (aHR = 0.52, 95% confidence interval = 0.44, 0.62). Hydrophilic statins exerted a stronger preventive effect against colon cancer. Regarding the statin type, lovastatin, pravastatin, and fluvastatin nonsignificantly reduced the colon cancer risk in the patients with COPD. Compared with the statin nonusers, the aHRs for colon cancer decreased in the individual statin users (rosuvastatin, simvastatin, and atorvastatin: aHRs = 0.28, 0.64, and 0.65, respectively). In the sensitivity analysis, statins dose-dependently reduced the colon cancer risk. Conclusions: Statins dose-dependently exert significant chemopreventive effects on colon cancer in patients with COPD, with rosuvastatin exerting the largest chemopreventive effect.