We also searched for a distinct correlation of concomitant GAS in different tumor types: only studies of EGFR-mutated NSCLC patients receiving TKIs and either PPIs or H2RAs and those with GI cancers receiving all PPIs and oral chemotherapy retained a significant correlation between GAS and poor survival (HR = 1.47, 95%CI 1.27–1.71; p < 0.01 and HR = 1.3, 95%CI 1.02–1.66; p = 0.04), while in the case of renal cell carcinoma, the correlation between GAS assumption and reduced survival was missing. This evidence concerns the gene EGFR and flatulence.