Association of statin use with clinical outcomes in patients with triple-negative breast cancer

Abstract

Background: Previous studies have examined the association of statin therapy and breast cancer outcomes with mixed results. The objective of this study was to investigate the clinical effects of incident statin use among individuals with triple-negative breast cancer (TNBC).

Methods: Data from the Surveillance, Epidemiology, and End Results-Medicare and Texas Cancer Registry-Medicare databases were used, and women aged ≥66 years who had stage I, II, and III breast cancer were identified. Multivariable Cox proportional hazards regression models were used to examine the association of new statin use in the 12 months after a breast cancer diagnosis with overall survival (OS) and breast cancer-specific survival (BCSS).

Results: When examining incident statin use, defined as the initiation of statin therapy in the 12 months after breast cancer diagnosis, a significant association was observed between statin use and improved BCSS (standardized hazard ratio, 0.42; 95% confidence interval [CI], 0.20-0.88; P = .022) and OS (hazard ratio, 0.70; 95% CI, 0.50-0.99; P = .046) among patients with TNBC (n = 1534). No association was observed with BCSS (standardized hazard ratio, 0.99; 95% CI, 0.71-1.39; P = .97) or OS (hazard ratio, 1.04; 95% CI, 0.92-1.17; P = .55) among those without TNBC (n = 15,979). The results were consistent when examining statin exposure as a time-varying variable.

Conclusions: Among women with I, II, and III TNBC, initiation of statin therapy in the 12 months after breast cancer diagnosis was associated with an OS and BCSS benefit. Statins may have a role in select patients with breast cancer, and further investigation is warranted.

Keywords: Surveillance, Epidemiology, and End Results-Medicare; breast cancer; statins; triple-negative breast cancer.

Figure 1.

CONSORT diagram for cohort selection

Figure 2.

Forest plot of hazard ratios for overall survival of incident statin use (yes versus no) within 1 year after diagnosis after multivariable adjustment in subgroups stratified by stage and triple negative subtype Stage 1 triple negative breast cancer (TNBC) cohort patients in the statin group did not have death due to breast cancer. Stage 1 non-TNBC cohort adjustment for age, race, state buy-in, endocrine therapy, radiation, chemotherapy, comorbidity, and baseline hypertension. Stage 2 TNBC and non-TNBC adjustment for age, race, education, state buy-in, residence area, endocrine therapy, radiation, chemotherapy, surgery, comorbidity, and hypertension pre-diagnosis. Stage 3 TNBC cohort adjustment for age, residence area, endocrine therapy, radiation, surgery, and comorbidity. Stage 3 non-TNBC cohort adjustment for age, residence area, endocrine therapy, radiation, surgery, and comorbidity.