biostudies-literatureUnknown10Wang RNatural Science Foundation of Zhejiang ProvinceEndocrine treatment plus CDK4/6 inhibitors have become standard of care for estrogen receptor positive (ER+) breast cancer. Although immune checkpoint inhibitors (ICIs) have shown promising antitumor activity in a variety of cancer types, only limited success has been achieved for metastatic breast cancer (mBC) patients, especially the ER+ subtype, which usually exhibit lower tumor mutation burden (TMB) compared with other subtypes and therefore perceived as immunologically quiescent. Here we present a case of an ER+/HER2- but TMB-high mBC patient who had significant response to combination therapy with anti-PD-1 antibody camrelizumab and vinorelbine and obtained partial response (PR) with a progression-free survival (PFS) of 5 months after failure of multiple lines of therapy. Our case indicates that TMB may serve as a potential biomarker in immunotherapy selection for normally immunologically "cold" tumors such as ER+ mBC, also molecular monitoring during the whole treatment course plays an important role in patient management.Frontiers in oncology588080https://www.ebi.ac.uk/biostudies/studies/S-EPMC7900143biostudies-literatureCase Report: Significant Response to Immune Checkpoint Inhibitor Camrelizumab in a Heavily Pretreated Advanced ER+/HER2- Breast Cancer Patient With High Tumor Mutational Burden.PMC7900143Ye WWYang YWang RXiang JCao WMChen SZou WBWang XJChen TfalseCase Report: Significant Response to Immune Checkpoint Inhibitor Camrelizumab in a Heavily Pretreated Advanced ER+/HER2- Breast Cancer Patient With High Tumor Mutational Burden.Endocrine treatment plus CDK4/6 inhibitors have become standard of care for estrogen receptor positive (ER+) breast cancer. Although immune checkpoint inhibitors (ICIs) have shown promising antitumor activity in a variety of cancer types, only limited success has been achieved for metastatic breast cancer (mBC) patients, especially the ER+ subtype, which usually exhibit lower tumor mutation burden (TMB) compared with other subtypes and therefore perceived as immunologically quiescent. Here we present a case of an ER+/HER2- but TMB-high mBC patient who had significant response to combination therapy with anti-PD-1 antibody camrelizumab and vinorelbine and obtained partial response (PR) with a progression-free survival (PFS) of 5 months after failure of multiple lines of therapy. Our case indicates that TMB may serve as a potential biomarker in immunotherapy selection for normally immunologically "cold" tumors such as ER+ mBC, also molecular monitoring during the whole treatment course plays an important role in patient management.2020-01-01T00:00:00Z20202024-11-05T20:50:25.66Z2021-03-02T08:15:06ZS-EPMC79001433363401510.3389/fonc.2020.588080