Trends in statin use and its association with mortality among older U.S. cancer survivors with and without coronary heart disease.

AIMS: Investigate the distribution of statin and its association with cause-specific mortality among older (aged 65 years or older) U.S. cancer survivors, stratified by coronary heart disease (CHD) status. METHODS: A retrospective cohort study utilized data from ten NHANES cycles (1999-2000 through 2017-2018) and mortality follow-up began from the date of survey participation and continued through December 31, 2019. Statin exposure was identified via a 30-day recall period at the time of the household interview. Mortality hazard ratio (HR) were estimated using Cox proportional hazards regression, and survival rates were assessed via Kaplan-Meier curves. Subgroup analyses were performed to explore potential effect modifiers including sex, smoking, alcohol consumption, diabetes, and hypertension. RESULTS: Among 2714 cancer survivors, the average age was 75.47, 1473 (54.27%) were men and 649 (23.91%) had CHD. The observed proportion of statin users tripled from 20.0% (1999-2000 cycle) to 56.0% (2015-2016 cycle) with distinct trends by CHD status and sex. Over a mean follow-up of 81 months, statin users with CHD exhibited significantly lower all-cause, cardiac, and cancer-related mortality proportions compared to non-users (52.0%vs.72.8%, 18.3% vs.25.9%, 11.5% vs. 18.0%, respectively, P < 0.05 for all). Statin use was associated with higher survival outcomes across all mortality categories, as demonstrated by Kaplan-Meier analysis (all log-rank p < 0.05). Model 2 (fully adjusted for sex, race, education level, marital status, PIR, alcohol consumption, smoking status, DM, and hypertension) showed that statin use in CHD patients was independently associated with lower all-cause (HR: 0.797, 95% CI: 0.705-0.901), cardiac (HR: 0.765, 95% CI: 0.594-0.984), and cancer-related mortality (HR: 0.774, 95% CI: 0.615-0.973), while, in the non-CHD group, statin use was associated with lower all-cause mortality (HR: 0.782, 95% CI: 0.673-0.909) but not with cardiac or cancer-related mortality. Significant interactions were observed in subgroup analysis for alcohol consumption and hypertension with all-cause mortality (all P < 0.05), with consistent benefits among CHD patients. CONCLUSION: Statin use was associated with lower all-cause, cardiac, and cancer-related mortality in older cancer survivors with CHD, but not with cancer-related mortality in those without CHD. These findings are hypothesis-generating and require prospective validation.