Pre-diagnostic statin use, lymph node status and mortality in women with stages I-III breast cancer
A partir des données du registre national irlandais des cancers portant sur 6 314 patientes atteintes d'un cancer du sein de stade I à III et à partir des données de prescriptions, cette étude évalue l'association entre l'utilisation de statines avant diagnostic et le statut ganglionnaire de la maladie ainsi que la mortalité spécifique ou la mortalité toutes causes confondues
Background : Recent meta-analyses suggest that pre-diagnostic statin use is associated with reduced breast cancer-specific mortality. Studies have shown that high breast tumour expression of the statin target (3-hydroxy-3-methylglutaryl coenzyme-A reductase) is associated with lymph-node negative cancer. Therefore, we examined the association between pre-diagnostic statin use and; lymph node status, breast cancer-specific and all-cause mortality. Methods : Women with stages I–III breast cancer were identified from the National Cancer Registry of Ireland (N=6 314). Pre-diagnostic statin users were identified from linked prescription claims data (N=2 082). Relative risks were estimated for associations between pre-diagnostic statin use and lymph node status. Hazard ratios (HR) were estimated for associations between pre-diagnostic statin use and breast cancer-specific and all-cause mortality. Results : Pre-diagnostic statin use was not associated with lymph node negative status at diagnosis. In multivariate analyses, pre-diagnostic statin use was associated with reduced all-cause (HR 0.78 95% confidence interval (CI) 0.69, 0.89) and breast cancer-specific mortality (HR 0.81 95% CI 0.68, 0.96). This reduction in cancer-specific mortality was greatest in statin-users with oestrogen (ER) receptor-positive tumours (HR 0.69 95% CI 0.55, 0.85). Conclusion : Patients with pre-diagnostic statin exposure had a significant reduction in breast cancer-specific mortality, which was even more pronounced in women with ER+ tumours.