A Prospective, Phase II Trial Using ctDNA to Initiate Post-operation Boost Therapy After Adjuvant Chemotherapy in TNBC

Inclusion Criteria: * Patient is ≥ 18 years-old at the time of consent to participate this trial * Stage II - III primary triple negative breast cancer patients(TNBC), TNBC is defined as ER \<=1%, PR \<=1%；HER2 receptor IHC=1, or IHC=2 and FISH negative. * positive ctDNA after curative surgery and/or adjuvant chemotherapy * ECOG 0-2 * If indicated, patient agree to receive adjuvant radiotherapy according to the institutional guidelines * Patient receives adjuvant chemotherapy according to the NCCN guidelines * Patient has available tumor tissue from the surgical specimen for next generation sequencing(NCS) * Patient agrees to give blood samples for ctDNA tests every 3 months in 5 years Exclusion Criteria: * Patient has previously received any PD1/PDL1 blockage treatment * Pregnant or breast-feeding (lactating) women or women who plan to become pregnant or breast-feed during the trial * Patient with distant metastases of breast cancer beyond regional lymph nodes (stage IV according to AJCC 8th edition) * Patient participates another interventional clinical trial * Patient has a concurrent invasive malignancy or a prior invasive malignancy whose treatment was completed within 3 years before randomization * Patient with autoimmune disease preventing the use of camrelizumab * Patient has any other concurrent severe and/or uncontrolled medical condition that would, in the Investigator's judgment, cause unacceptable safety risks, contraindicate patient participation in the clinical trial or compromise compliance with the protocol