Post-diagnosis statin use and breast recurrence sites in early stage breast cancer survivors

Abstract

To the Editor, We read the article by Kwan et al. [1] in which they showed an inverse association between post-diagnosis, lipophilic statin use and risk of breast cancer recurrence in a prospective cohort study of early stage breast cancer survivors. However, information related to the specific recurrence sites were not discussed in their study. Evidence from animal models suggests that activation of osteoclastmediated bone resorption is an essential step in the process of bone metastasis [2]. Bisphosphonates are class of agents most frequently used to reduce skeletal-related events in patients with bone metastases by inhibiting osteoclast activity through inhibition of mevolanate pathway. Relationship between statins and nitrogen-containing bisphosphonates has been established. Both drugs interfere with the same metabolic pathway. Both exert their activity in the mevalonate pathway This pathway leads to cholesterol synthesis and to protein prenylation, adding a lipid chain to transpeptidases such as Ras and Ras-like transpeptidases in the osteoclast membrane which in turn leads to activation of osteoclasts [3]. Furthermore, some studies showed that bisphosphonates might reduce or prevent the incidence of bone metastases by inhibiting tumour-induced osteoclastic resorption of bone when they are used as an adjuvant treatment of breast cancer [4, 5]. Therefore, we suggest that post-diagnosis, lipophilic statin use may reduce bone metastases more than other recurrence sites in early stage breast cancer survivors.