Main results
For OS, all 14 studies including 6716 cancer patients receiving ICIs treatment are analyzed for influence of concomitant PPIs exposure on OS. The fixed effect model was applied since no obvious heterogeneity existed (Q test P=0.362, I2=8.288). The result demonstrated that concomitant PPIs use had significantly shorter OS among patients receiving ICIs therapy compared to PPIs-unexposed ones, the pooled HR for OS was 1.388 (95%CI:1.278-1.498, P<0.001) (Figure 2A).
Nine studies including 4866 patients undergoing ICIs therapy are available for analysis of effect of concomitant PPIs use on PFS. The fixed-effect model was applied since the heterogeneity was acceptable (Q test P=0.109, I2=38.888). Similarly, the result indicated that PPIs use could also shorten PFS of cancer patients receiving ICIs treatment, the pooled HR for PFS was 1.285(95%CI:1.193-1.384, P<0.001) (Figure 2B).