The study is to determine the prevalence of potential chemo-response related genes mutation in TNBC patients between pCR and SD/PD group, which achieved after NAC; and to evaluate potential relationship between these gene mutations and NAC-response in TNBC patients.Based on the results,we can further characterize TNBC from a phenotypical and molecular perspective, in order to identify potential new target agents and to individualize the treatment.

This is single centre，exploratory，parallel and retrospective study to analysis the mutation and expression of tBRCA1/2 and other potential genes in triple-negative breast cancer. Patients received neoadjuvant chemotherapy with paclitaxel and carboplation are enrolled in this study. The participants are required to have clinical stage II or III breast cancer with a clinical or radiographically measurable residual tumor after core biopsy. We will enroll the patients of pCR or SD/PD, which achieved after complete NAC. Every group will enroll 50 patients. This study is to identify relationship between different gene mutations and expression, which may be targeted with currently available investigational drugs, and chemo-response.

Patients who will fulfil all inclusion/exclusion criteria. We conducted a retrospective chart review of the 100 patients.

Inclusion Criteria:

Patients receiving neoadjuvant chemotherapy with paclitaxel and carboplation are enrolled in this study.

• (1) histologically confirmed mainly invasive breast carcinoma
• (2) a unilateral and non-inflammatory tumors
• (3) status of ER, PR and HER-2 are available and negative
• (4) The participants are required to have clinical stage II or III breast cancer with a clinical or radiographically measurable residual tumor after core biopsy.
• (5)patients had pathological evaluation after NAC
• (6) the pathologic tissues are available for immunohistochemistry and next generation sequencing

Exclusion Criteria:

• (1) carcinoma in situ
• (2) received less than 4 cycles neoadjuvant chemotherapy