Lipid-lowering drug use, duration of use, and age at first use is associated with a lower risk of colorectal cancer mortality in men and women in the Atherosclerosis Risk in Communities (ARIC) Study
Michael T Marrone1, John R Barber1, Alison M Mondul2, Anna E Prizment3, David Couper4, Corinne E Joshu1, Elizabeth A Platz1
1Johns Hopkins University School of Public Health, Baltimore, MD, United States
2University of Michigan School of Public Health, Ann Arbor, MI, United States
3University of Minnesota, Minneapolis, MN, United States
4University of North Carolina Gillings School of Public Health, Chaple Hill, NC, United States
Background: While lipid-lowering drugs, particularly statins, are associated with a modestly reduced risk of developing colorectal cancer (CRC), the association of lipid-lowering drug use, duration of use, and age at first use with CRC mortality in men and women without the diagnosis at baseline, has not been well studied. Further, whether associations are similar across race is unknown. Thus, we aimed to characterize the association between lipid-lowering drug use and CRC mortality in men and women and by race. We classified lipid-lowering drug use in a time-dependent manner as current use, duration of use, and age at first use.

Methods: We conducted a prospective cohort study of 14,428 cancer-free men and women attending visit 2 (1990-1992) of the Atherosclerosis Risk in Communities (ARIC) Study. Death from CRC was ascertained from the underlying cause on death certificates. Follow-up began at visit 2 and ended at date of death or 12/31/2015, whichever came first. There were 384 incident CRC cases and 144 deaths in 290,249 person-years. Cox regression was used to estimate relative hazards (HR) and 95% confidence intervals (CI) for CRC incidence and death adjusting for age, sex, education, race and field center, BMI, smoking status and pack years, alcohol use, red and processed meat consumption, aspirin use, and family history of any cancer and family history of CRC overall and by gender and race. Current lipid-lowering medication use, duration of use (<15 years, ≥15 years), and age at first use (<50, 50-59, 60-69, and ≥70 years of age) were modeled as time-dependent variables.

Results: Mean age was 57 years and mean BMI was 28.1 kg/m2; 54.9% were women and 27.9% were Black. By visit 4 (1996-98), after an average of 6 years of follow-up, 22% of participants were using lipid-lowering drugs. Compared to never users, current use was associated with 53% lower risk of CRC death (HR 0.47; 95%CI 0.32-0.71). Inverse associations were present in both men (HR 0.59; 95%CI 0.35-0.99) and women (HR 0.37; 95%CI 0.20-0.69) and in Black (HR 0.44; 95%CI 0.19-1.00) and White (HR 0.49; 95%CI 0.31-0.77) participants. Inverse associations were consistent across different patterns of duration of use and was inverse irrespective of age at first use. Current use was also associated with a lower risk of CRC incidence (HR: 0.72; 95%CI 0.57-0.92).

Conclusions: Current use of lipid-lowering drugs was associated with a statistically significant lower risk of dying from CRC in participants without cancer at baseline, including men and women and in Black and white participants, irrespective of the duration (15 year intervals) or age at first use.

Support: NHLBI contracts, NCI grants, NPCR

Session: Liver, Pancreas, Colon, and Other Gastrointestinal Cancers (Virtual Poster Session)