Exploratory evaluation of immunotherapy response and medication use in endometrial and cervical carcinoma

217 CC and EC patients were treated with ICIs during this study period; 32 % (n = 71) had CC, and 67 % (n = 146) had EC. There was a significant difference in ICI complete response between CC patients who did and did not use oral steroids during treatment. Of CC patients who achieved a complete response, 28 % (n = 7) used steroids vs. 13.6 % (n = 6) of non-steroid users (Fisher's exact p = 0.045). In patients with EC, proton pump inhibitor (PPI) use was associated with ICI response, with 43.8 % (n = 21) of PPI users achieving a complete response vs. 16.3 % (n = 15) of non-PPI users (chi-squared p = 0.002). PPI use in the EC cohort was associated with improved progression-free survival and overall survival (log-rank p < 0.05). This was also demonstrated among mismatch repair-deficient EC patients where PPI use during ICI therapy significantly associated with both PFS (HR 0.26, 95 % CI 0.12-0.55; p < 0.001) and OS (HR 0.22, 95 % CI 0.08-0.59; p < 0.001).Conclusion(s)In this retrospective cohort study of EC and CC patients treated with ICI therapy, medication use, specifically PPIs and oral steroids, was seen to have a significant positive effect on ICI response, PFS, and OS.