The goal of this clinical trial is to learn about the efficacy and safety of short-term sintilimab in combination with taxane and carboplatin for neoadjuvant therapy in female early-stage triple-negative breast caner patients aging from 18 to 70 years with unilateral and invasive primary lesions above 1cm. The main questions it aims to answer are:

1. Does short-term sintilimab in combination with taxane and carboplatin lead to acceptible pathological complete response (pCR) rates, objective response rates (ORR), event-free survival (EFS) and overall survival (OS)?
2. Does short-term sintilimab in combination with taxane and carboplatin lead to less adverse events than regular-term ICIs reported in literature?

Participants will be given 2 cycles of sintilimab, in combination with 4 cycles of taxane and carboplatin before surgery. An optional core-needle biopsy is performed after completing 2 cycles of sintilimab. All participants will be given regular follow-up post surgery according to ASCO guidelines.

Inclusion Criteria:

1. Age: 18-70 years, female;

2. Unilateral, invasive, primary breast cancer, T≥1cm, cN0-3, M0;

3. Immunohistochemistry(IHC): ER, PR<10%; HER-2 IHC "0", OR IHC "+", OR IHC "++" AND fluorescence in situ hybridization (FISH) negative;

4. At least one measurable lesion according to RECIST V1.1;

5. Newly or recently-collected core needle biopsy specimen of the primary lesion available for PD-L1 status determination;

6. ECOG score 0 or 1 within 10 days prior to drug administration;

7. Currently not pregnant or breastfeeding, and meet at least one of the following conditions:

   1. NOT women of childbearing potential (WOCBPs).
   2. WOCBPs that strictly adopt contraceptive measures during treatment and within at least 6 months after last drug administration.

8. Organs well-functioned according to laboratory examination and imaging;

9. Having good compliance with treatment plans, being capable of understanding the research process, and having signed a written informed consent.

Exclusion Criteria:

1. Bilateral invasive breast cancer or metastatic (Stage IV) breast cancer;

2. With severe cardiovascular conditions:

   1. Myocardial infarction, acute coronary syndrome or PCI/CABG within 6 months;
   2. Current NYHA II-IV congestive heart failure (CHF) or past history of NYHA III-IV CHF.

3. Immunodeficiency, or undergoing systemic steroid therapy or any form of immunosuppressive therapy within 7 days prior to drug administration;

4. Active autoimmune diseases requiring systemic treatment within the past 2 years;

5. Known history of active tuberculosis caused by Bacillus Tuberculosis;

6. History of non infectious pneumonia requiring steroid treatment, or active pneumonia of all types;

7. Severe systemic infections, or other serious illnesses;

8. History of other malignant tumors within the past 5 years, except cured cervical carcinoma in situ and non-melanoma skin cancer;

9. Known history of human immunodeficiency virus (HIV) infection;

10. Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection;

11. Known allergy or intolerance to therapeutic drugs or their excipients;

12. History of receiving cytotoxic chemotherapy, endocrine therapy, biological therapy or radiation therapy for any reason;

13. History of receiving anti PD-1, anti PD-L1, or anti PD-L2 drugs; or targeted drugs that act on stimulating or co-inhibitory T cell receptors (CTLA-4, OX 40, CD137 etc.);

14. Enrolled in a study of an investigational drug/instrument and given intervention within 4 weeks prior to drug administration for regular drugs/instruments and within 12 months for anticancer or anti-proliferative drugs/instruments;

15. Live vaccine (including but not limited to the following: measles, mumps, rubella, chickenpox/shingles, yellow fever, rabies, BCG, typhoid vaccines, and nasal influenza vaccines such as FluMist®) inoculation within 30 days prior to drug administration;

16. History of mental illness or drug abuse that may affect compliance with trial requirements;

17. During pregnancy or breastfeeding, or WOCABs that refuse to adopt strict contraceptive measures;

18. Deemed to be not appropriate for participating in this study by researchers.