The goal of this clinical trial is to learn about the mutation spectrum of homologous recombination repair pathway genes and its instructive significance in the treatment of Chinese breast cancer patients.

The main questions it aims to answer are:

1. What is the mutation spectrum of homologous recombination repair pathway genes in Chinese breast cancer patients?
2. Does homologous recombination repair pathway gene mutation have an impact on patient outcome (breast cancer recurrence, neoadjuvant chemotherapy efficacy, treatment decisions, etc.) ? There is no intervention on participants, but all participants will be given regular follow-up post surgery according to ASCO guidelines.

Inclusion Criteria:

1. Pathology-confirmed breast cancer patients who meet at least one of the criteria below:

   • Triple-negative breast cancer
   • Age ≤ 50 years
   • Male breast cancer
   • With personal or family history of malignancy: breast cancer, ovarian cancer, prostate cancer, pancreatic cancer, other malignancies
   • HER-2 negative recurrent or metastatic breast cancer
   • HER-2 negative high-risk breast cancer:

   A: Neoadjuvant phase: non-pathological complete response for triple-negative breast cancer; non-pathological complete response AND CPS+EG score ≥ 3 for hormone receptor positive breast cancer B: Adjuvant phase: ≥ pT2 or ≥ pN1 for triple-negative breast cancer; ≥ 4 lymph node metastasis for hormone receptor positive breast cancer

2. Having been or intended to be tested for germline and (or) somatic homologous recombination repair gene mutations

3. Consent to providing medical charts and homologous recombination repair gene testing results, and being cooperative for long-term follow-up

Exclusion Criteria:

1. Homologous recombination repair gene testing results unavailable
2. Other factors deemed by the investigators that may sabotage the study

Breast cancer patients