Letter to Editor KMJ-027/012
Individual Statins on the Risk of Colorectal Cancer: A Population-Based Observation in Taiwan
Running head: colorectal cancer and statins
Shih-Wei Lai, MD1,2; Kuan-Fu Liao, MD and MS3,4,5;
Hsueh-Chou Lai, MDand MS6,7; Chih-Hsin Muo, MPH 8,9;
Fung-Chang Sung, PhD, MPH 8,9
(The first two authors contributed equally to this study.)
1School of Medicine, 6School of Chinese Medicine, and 8Department of Public
Health, China Medical University, Taichung, 404, Taiwan
2Department of Family Medicine, 7Department of Internal Medicine, and 9Management Office for Health Data, China Medical University Hospital,
Taichung, 404, Taiwan
3Department of Internal Medicine, Taichung Tzu Chi General Hospital,
Taichung, 427, Taiwan
4School of Medicine, Tzu Chi University, Hualien, 970, Taiwan
5Department of health care administration, Central Taiwan University of
Science and Technology, Taichung, 406, Taiwan Corresponding author:
Fung-Chang Sung, PhD, MPH Professor
Department of Public Health, China Medical University No. 91, Hsueh-Shih Road, Taichung, 404, Taiwan Phone: 886-4-2205-4070
Fax: 886-4-2201-9901
E-mail: [email protected]
To editor,
Whether statins can increase or decrease colorectal cancer risk remains inconclusive. Therefore, a population-based case-control study using database from the National Health Insurance program in Taiwan was
designed to explore the effects of the individual statins on the risk of colorectal cancer. The insurance program details can be found in previous studies . In this study, there were 3498 patients aged 20 years or older with newly diagnosed colorectal cancer (International Classification of Diseases 9th
Revision-Clinical Modification, ICD-9 codes 153 and 154 and A code A-093 and A-094) as cases (2010 men and 1488 women, mean age 65.9 years, standard deviation 13.8 years), and 10492 subjects without colorectal cancer frequency matched with sex, age (per 5 years) and index date as controls (6028 men and 4464 women, mean age 65.3 years, standard deviation 14.0 years), from 2000 to 2009. We measured the association between colorectal cancer risk and statins use, including simvastatin, lovastatin, pravastatin, fluvastatin, atorvastatin, and rosuvastatin.
After adjustment for covariates, the adjusted OR of colorectal cancer was 1.01 (95% CI 0.90-1.14) for the stains-use group, when compared to the group with non-use of statins. In sub-analysis, use of fluvastatin (OR 0.76, 95% CI 0.59-0.97) could show statistically significant reduction of colorectal cancer risk. Use of the other statins, including simvastatin (OR 0.94, 95% CI 0.78-1.12), lovastatin (OR 0.99, 95% CI 0.82-1.20), pravastatin (OR 1.22, 95% CI 0.90-1.64), atorvastatin (OR 0.97, 95% CI 0.82-1.14), and rosuvastatin (OR 1.12, 95% CI 0.81-1.54), could not show a significant association with colorectal cancer.
To date, inconsistent evidence exists about the role of statins on the risk of colorectal cancer. Two case-control studies in Israel and in Germany, statins use could correlate with risk reduction of colorectal cancer by 50% (95% CI 0.40-0.63) and 35% (95% CI 0.43-0.99), respectively . However, a series of nested case-control studies in UK showed that statins use for more than 4 years could be associated with 1.2-fold increased risk of colorectal cancer (95% CI 1.10-1.38) . In other studies, no significant association was noted between statins use and colorectal cancer risk . In this present study, however, we found only use of fluvastatin could show 24% reduction of colorectal cancer risk. Especially when using fluvastatin ≥ 6 months, the risk could further be reduced to 39% (95% CI 0.42-0.90). A cohort study by Simon and et al in US, women with use of lovastatin were associated with 38% reduction of colorectal cancer risk (95% CI 0.39-0.99) . Because of inherent
limitation of a case-control study, we cannot address any plausible explanation about these above conflicting results. However, a review by Jacobs and et al, because colorectal cancer is a multi-factorial disease, the authors suggest whether statins has inhibiting effect or neoplasm-promoting effect depends on the underlying molecular subtypes of subjects studied . That may at least partially explain why some studies showed a protective effect of statins on colorectal cancer, but the others showed a harmful effect. Further studies are required to better understand the role of statins on the molecular pathophysiology of colorectal cancer.
We conclude that use of fluvastatin may correlate with 24% decreased risk of colorectal cancer. Use of the other statins can not show a significant association with colorectal cancer.
Funding: This study was supported in part by grants from Taiwan
Department of Health Clinical Trial and Research Center of Excellence
(DOH101-TD-B-111-004), the Cancer Research Center of Excellence
(DOH 101-TD-C-111-005), and the National Science Council (NSC 100-2621-M-039-001). The funding agencies did not influence the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgements: The authors thank the National Health Research Institute in Taiwan for providing the insurance claims data.
Conflict of Interest Statement: The authors disclose no conflicts of interest.
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