Statin Use After Colorectal Cancer Diagnosis Reduces Colorectal Cancer–Specific and All-Cause Mortality
In a UK population-based cohort study reported in the Journal of Clinical Oncology, Cardwell et al found that statin use after diagnosis of colorectal cancer was associated with a 29% reduction in colorectal cancer–specific mortality and a 25% reduction in all-cause mortality. Improvements were greater in patients taking statins for >1 year.
Study Details
The study involved a cohort of 7,657 patients with newly diagnosed stage I to III colorectal cancer identified from 1998 to 2009 from the UK National Cancer Data Repository. The UK Clinical Practice Research Datalink provided prescription records, and the UK Office of National Statistics provided mortality data through 2012.
A total of 2,662 patients (35%) had ever used statins. Statin users were more likely to be diagnosed more recently, be older, be men, have a smoking history, have greater body mass index, have comorbidities (including cerebrovascular disease, diabetes, and myocardial infarction), and use other medications (eg, aspirin, ACE inhibitors, and metformin). A smaller proportion of statin users had stage III disease (36% vs 43%), but users and nonusers were otherwise generally matched for colorectal cancer stage and grade.
Improved Survival
Average follow-up after diagnosis was 5 years. A total of 1,647 colorectal cancer–specific deaths occurred. Statin use after diagnosis was associated with significantly reduced risk of colorectal cancer–specific death (hazard ratio [HR] = 0.72, 95% confidence interval [CI] = 0.64–0.81), including reduced risk in those with 1 to 365 daily defined doses (ie, < 1 years’ use; HR = 0.79, 95% CI = 0.68–0.93) and in those with > 365 daily defined doses (HR = 0.65, 95% CI = 0.56–0.77). The observed effects appeared to be similar across statin types. Statin users also had a significant reduction in all-cause mortality (HR = 0.88, 95% CI = 0.81–0.96).
Significant Benefits in Adjusted Analysis
Multivariate analyses were performed to adjust for year of diagnosis, age at diagnosis, sex, stage, surgery within 6 months, radiotherapy within 6 months, chemotherapy within 6 months, site (colon or rectum), comorbidities (before diagnosis, including cerebrovascular disease, chronic pulmonary disease, congestive heart disease, diabetes, myocardial infarction, peptic ulcer disease, peripheral vascular disease, and renal disease), and other medication use after diagnosis. On this analysis, statin use was associated with a significant 29% reduction in risk for colorectal cancer–specific mortality (adjusted HR = 0.71, 95% CI = 0.61–0.84) and a 25% reduction in risk for all-cause mortality (HR = 0.75, 95% CI = 0.66–0.84). A dose-response effect was observed, with a greater reduction in risk observed with statin use > 1 year (adjusted HR = 0.64, 95% CI = 0.53–0.79).
Among patients who had not used statins prior to colorectal cancer diagnosis, the adjusted hazard ratio among statin users for colorectal cancer–specific mortality was 0.66 (95% CI = 0.50–0.85). The effect was somewhat smaller in analysis excluding statin prescriptions in the year before death (adjusted HR = 0.77, 95% CI = 0.66–0.90) and was further attenuated when prescriptions in the 2 years before death were excluded (adjusted HR = 0.84, 95% CI = 0.69–1.02). However, the effect remained significant for patients in the latter analysis who had > 365 defined daily doses (adjusted HR = 0.75, 95% CI = 0.56–0.99).
A significant preventive effect in colorectal cancer–specific mortality was also observed among patients who used statins prior to diagnosis (adjusted HR = 0.86, 95% CI = 0.79–0.93).
The investigators concluded, “In this large population-based cohort, statin use after diagnosis of colorectal cancer was associated with longer rates of survival.”
Chris R. Cardwell, PhD, of Royal Victoria Hospital, Belfast, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by the Health and Social Care Research and Development (Public Health Agency, Northern Ireland). The authors indicated no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
