Table 1.

Summary of all the included studies in the present meta-analysis.

Author Name [Reference]	Year	Region	Number of Patients Receiving Antacids	Number of Patients No Antacids	Type of ICIs	Type of Antiacids
Hakozaki [26]	2019	Japan	47	43	Nivolumab	PPIs or H2RAs
Zhao [27]	2019	China	40	69	Nivolumab Pembrolizumab SHR-1210	PPIs
Chalabi [28]	2020	Worldwide	234	523	Atezolizumab	PPIs
Peng [29]	2021	United States	89	144	Nivolumab Pembrolizumab Nivolumab plus ipilimumab	PPIs
Rounis [30]	2021	Greece	23	43	Atezolizumab Nivolumab Pembrolizumab	PPIs
Cortellini [31]	2021	Italy	547	465	Atezolizumab Nivolumab Pembrolizumab	PPIs or H2RAs

Abbreviations: H2RAs: histamine-2-receptor antagonists; ICIs: immune checkpoint inhibitors; PPIs: proton pump inhibitors