Abstract
Background
Immunotherapy has revolutionized the treatment of malignant tumors. However, limited clinical data are available to report the efficacy of immune checkpoint inhibitors (ICIs) on Epstein-Barr virus-associated gastric carcinoma.
Methods
In this study, we report a case series of five patients with metastatic Epstein-Barr virus-associated gastric carcinoma who were treated with ICIs and to perform a pooled analysis of published cases to investigate the efficacy of ICIs in Epstein-Barr virus-associated gastric carcinoma patients.
Results
Between 2018 and 2020, five metastatic gastric cancer patients with EBV positivity who received PD-1 antibodies treatment were included in the analysis at the authors’ institution. Furthermore, we performed a pooled analysis of the contemporary literature. In our case series, two patients experienced partial response (PR); one patient achieved complete response (CR), whereas two patients had progression disease (PD), resulting an ORR of 60%. In the pooled analysis of all 36 patients, ORR was 48.6% (17/35). For the first line and later lines, it was 75% (3/4) and 45.2% (14/31) respectively. The ORR was 46.7% (14/30) for ICIs monotherapy and improved to 60% (3/5) by combination with chemotherapy.
Conclusions
These results demonstrated that an EBV-positive status was a reliable biomarker for immunotherapy in metastatic gastric cancer, especially for monotherapy. Immunotherapy combined with chemotherapy may be a better strategy, warranting further large-scale clinical trials for validation.