International Breast Cancer Biomarker,Standard of Care and Real World Outcomes Study
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.
Background/Rationale: Within the setting of metastatic human epidermal growth factor receptor
 2 negative (HER2-ve) breast cancer limited epidemiological data exist on the prevalence of
 pathogenic mutations of breast cancer susceptibility gene (BRCA) and other homologous
 recombination repair (HRR) genes. There are also limited data on the treatments and clinical
 outcomes of patients with such germline and somatic genetic profiles, particularly within
 this setting. This epidemiologic study will estimate the prevalence of germline breast
 susceptibility gene (gBRCA) mutations among metastatic HER2-ve patients who have commenced
 1st line systemic cytotoxic chemotherapy and, at that time, are considered to have exhausted
 hormone therapy options (if hormone receptor positive [HR+ve]), per investigator's opinion.
 Among those patients with a gBRCA gene mutation, treatment patterns and clinical outcomes
 will be described. This study may also explore the prevalence of somatic BRCA (sBRCA)
 mutations and other HRR gene mutations among metastatic HER2-ve patients who have commenced
 1st line systemic cytotoxic chemotherapy. The treatment patterns and clinical outcomes may be
 described among those patients with a sBRCA gene mutation and those with other HRR gene
 mutations.
Inclusion Criteria:

 1. Provision of signed, written and dated informed consent.

 2. Adult females (according to the age of majority/adulthood as defined by local
 regulations).

 3. Histologically or cytologically confirmed HER2-ve breast cancer with evidence of
 metastatic disease.

 4. Initiated treatment with 1st line systemic cytotoxic chemotherapy (not hormonal
 therapy) for metastatic breast cancer in the last 90 days and, at that time, are
 considered to have exhausted hormone therapy options (if HR+ve).

 Exclusion Criteria:

 1. Previous enrolment in this study.

 2. Involvement in the planning and/or conduct of this study (applies to both AstraZeneca
 staff and/or staff at the study site).

 3. Current participation in a clinical study with an investigational oncology product.

 4. Previous PARPi therapy, including, but not limited to, participation in a previous
 clinical study that included PARPi therapy.

 5. Current commencement of PARPi treatment.