What is the Current Effectiveness of Olaparib for Breast Cancer Patients with a BRCA Mutation? A Systematic Review

Abstract

Background:The Poly (ADP-ribose) polymerase inhibitor olaparib, acts against cancer cells in people with breast cancer pre-disposition gene mutations (BRCAm). Despite US and EU approval as a therapy for ovarian cancer patients with BRCAm, but research into olaparib therapy for breast cancer patients with BRCAm is in its infancy.Objective:As no systematic review has yet been undertaken to synthesise clinical trials looking at olaparib as a therapy for breast cancer patients with BRCAm, this systematic review aims to establish the current effectiveness of olaparib as a treatment for these patients.Methods:CINAHL, MEDLINE, Royal College of Nursing, Cochrane Library, Joanna Briggs Institute, Centre for Reviews and Dissemination, Internurse, Embase, Google Scholar and PubMed databases were searched, supplemented by a grey literature search, hand searching and cross-referencing. Authors independently reviewed and graded the studies also using Kmetet al. scoring system.Results:One long-term case study and six clinical trials were included. Heterogeneity prevented statistical meta-analysis, meaning only narrative synthesis was possible. The overall clinical benefit of olaparib appears to be greater and longer lived in BRCAm carriers compared to BRCAwt, and also when compared to standard chemotherapy treatments.Conclusion:Implications for nursing: nurses working in this field should be aware that the most compelling results were found in the subset of patients who harbour a BRCA mutation, meaning that olaparib should be regarded as a clinically effective potential therapy for these patients. Larger, longer-term trials including comparator arms are required to demonstrate benefits including overall survival, adverse effects and quality of life.