Cohort Study of Patients With HER2-negative MBC and BRCA 1/2 Pathogenic Mutation

Epidemiologic Evaluation and Clinical Outcomes for HER2-negative Metastatic Breast Cancer (MBC) Patients With Germline BRCA1 and 2 Pathogenic Mutation in Korea

The purpose of this study is to investigate the prevalence germline pathogenic BRCA1/2 mutation in a large group of potential candidate of PARP inhibitors, among the unselected patients with HER2-negative unresectable locally advanced or metastatic breast cancer.

This is a multicenter, prospective, non-interventional study on the prevalence of germline pathogenic BRCA1/2 mutation (Blood) and somatic pathogenic BRCA1/2 mutation (Tissue, optional) in patients with HER2-negative unresectable locally advanced or metastatic breast cancer.

1. For the assessment of germline mutational status of BRCA1 and BRCA2, (1)Collect peripheral blood from each subject. (2) Extract DNA from the collected blood. (3)From the extracted DNA, germline BRCA1/2 mutational status will be assessed by next generation sequencing(NGS) using NGeneBioBRCAaccuTest®
2. For the assessment of somatic mutational status of BRCA1 and BRCA2, (1)Collect FFPE from about 100 subjects. (2) Extract DNA from the FFPE. (3)From the extracted DNA, somatic BRCA1/2 mutational status will be assessed by next generation sequencing(NGS) using NGeneBioBRCAaccuTest®
3. Collect variables on the patients and compare clinical outcomes (Overall survival, Invasive Disease-free survival, Distant Disease-free survival, Progression free survival) that can be affected by clinicopathologic characteristics and type of treatment.

Inclusion Criteria:

• Age ≥ 20 years old
• Histologically confirmed, unresectable locally advanced or metastatic breast invasive carcinoma
• Human Epidermal Growth Factor Receptor 2 (HER2) negative breast cancer
• Germline mutational status of BRCA1 and/or BRCA2 can be known or unknown
• Signed written informed consent
• The patient is regarded as good candidate for active palliative management at time of enrollment. The patient with terminal cancer which is not appropriate for further endocrine treatment or chemotherapy cannot be enrolled to this study.

Exclusion Criteria:

• HER2 positive breast cancer
• Amenable to curative surgery