title: Statin use and breast cancer survival: a nationwide cohort study from Finland.
abstract: Recent studies have suggested that statins, an established drug group in the prevention of cardiovascular mortality, could delay or prevent breast cancer recurrence but the effect on disease-specific mortality remains unclear. We evaluated risk of breast cancer death among statin users in a population-based cohort of breast cancer patients. The study cohort included all newly diagnosed breast cancer patients in Finland during 1995-2003 (31,236 cases), identified from the Finnish Cancer Registry. Information on statin use before and after the diagnosis was obtained from a national prescription database. We used the Cox proportional hazards regression method to estimate mortality among statin users with statin use as time-dependent variable. A total of 4,151 participants had used statins. During the median follow-up of 3.25 years after the diagnosis (range 0.08-9.0 years) 6,011 participants died, of which 3,619 (60.2%) was due to breast cancer. After adjustment for age, tumor characteristics, and treatment selection, both post-diagnostic and pre-diagnostic statin use were associated with lowered risk of breast cancer death (HR 0.46, 95% CI 0.38-0.55 and HR 0.54, 95% CI 0.44-0.67, respectively). The risk decrease by post-diagnostic statin use was likely affected by healthy adherer bias; that is, the greater likelihood of dying cancer patients to discontinue statin use as the association was not clearly dose-dependent and observed already at low-dose/short-term use. The dose- and time-dependence of the survival benefit among pre-diagnostic statin users suggests a possible causal effect that should be evaluated further in a clinical trial testing statins' effect on survival in breast cancer patients.
authors.affiliation: University of Tampere, School of Medicine, Tampere, Finland; Tampere University Hospital, Department of Urology, Tampere, Finland.
authors.forename: Teemu J
authors.initials: TJ
authors.lastname: Murtola
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Department of Epidemiology, Baltimore, Maryland, United States of America; Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore Maryland, United States of America.
authors.forename: Kala
authors.initials: K
authors.lastname: Visvanathan
authors.affiliation: University of Helsinki, Helsinki, Finland.
authors.forename: Miia
authors.initials: M
authors.lastname: Artama
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Vainio
authors.affiliation: University of Tampere, School of Health Sciences, Tampere, Finland; The Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D005387:Finland; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D008875:Middle Aged; D016019:Survival Analysis
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors