Abstract 1716P
Background
Cancer patients receive proton pump inhibitors (PPIs) to protect against the adverse gastric effects of anti-cancer medications. With this regard, PPIs are frequently prescribed to cancer patients irrespective of their indications. However, alterations in gastric pH levels may affect the absorbtion of oral anti-cancer drugs.
Methods
We included 80 metastatic CRC patients treated with regorafenib in this study. Patients were divided into two categories according to their PPI receiving status. The co-primary endpoints were overall survival (OS) and progression-free survival (PFS). The secondary endpoints were response rates and safety. To exclude immortal time bias in survival analyses, we compared PPI non-user patients with all patients.
Results
There were 45 and 35 patients in the PPI non-user and user groups. Baseline characteristics were similar in each group. At the median 5.9 months follow-up, the median OS was similar in PPI non-user and all patients (5.9 months, [95% confidence interval [CI]:2.7-9.2] in PPI non-user patients; 7.4 months [95% CI:5.4-9.5] in all patients; p=0.9). The median PFS was also similar in PPI non-user and all patients (4.2 months [95% CI:3.5-4.9] in PPI non-user patients; 4.0 months [95% CI:2.6-5.3] in all patients; p=0.9). The objective response rate was 26.7% and 20% in PPI non-user and user patients. The rates of any grade AEs and AEs leading to treatment discontinuation were higher in PPI user patients than non-user patients (Table). Table: 1716P
Adverse events (AEs)
| PPI Non-user n=45 (%) | PPI User n=35 (%) | ||||
| 1-2 | 3 | 1-2 | 3 | ||
| Any | 15 (33.3) | 10 (22.2) | 15 (42.8) | 12 (34.2) | |
| Hand-Foot Syndrome | 4 (8.8) | 0 (0) | 3 (8.6) | 0 (0) | |
| Fatigue | 7 (15.5) | 4 (8.8) | 9 (25.7) | 6 (17.1) | |
| Hypertension | 1 (2.2) | 2 (4.4) | 1 (2.8) | 1 (2.8) | |
| Diarrhea | 0 (0) | 1 (2.2) | 2 (5.7) | 0 (0) | |
| Skin Rash | 3 (6.6) | 2 (4.4) | 1 (2.8) | 3 (8.6) | |
| Thrombosis | 0 (0) | 0 (0) | 0 (0) | 1 (2.8) | |
| AEs Leading to Treatment Discontinuation | 9 (20.0) | 15 (42.8) |
Conclusions
To our knowledge, this was the first report assessing the effect of PPIs on survival outcomes and AEs profile among CRC patients treated with regorafenib. This study showed that regorafenib combined with PPI was not associated with worse survival outcomes in CRC patients. However, AEs rates were higher in PPI user patients than PPI non-user patients. Of note, a multicenter study is conducting to obtain more accurate results with more patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.