International Breast Cancer Biomarker,Standard of Care and Real World Outcomes Study

BREAKOUT -International Breast Cancer Biomarker, Standard of Care and Real World Outcomes Study BREAKOUT is a prospective cross-sectional cohort study of human epidermal growth factor receptor 2 negative metastatic breast cancer patients who have started 1st line systemic cytotoxic chemotherapy. The study will estimate the prevalence of germline breast cancer susceptibility gene in an otherwise unselected population, describe the treatments administered and estimate the associated clinical outcomes of overall survival and progression-free survival amongst mutation carriers within the context of a low poly ADP ribose polymerase inhibitor treatment setting. Other exploratory analyses may be undertaken to describe somatic breast cancer susceptibility gene and other homologous recombination repair gene mutations.