Influence of proton pump inhibitors on the pathological response of rectal cancer: a multicentre study

Background

The standard neoadjuvant therapy for rectal cancer involves fluoropyrimidines and radiotherapy and, most recently, total neoadjuvant therapy (TNT). A drug-drug interaction between fluoropyrimidines and proton-pump inhibitors (PPI) was suggested, with a negative impact on oncological outcomes in breast, colon and gastric cancers. Little is known about such an effect on rectal tumours. We aimed to evaluate the impact of PPI utilisation on the pathological response after chemoradiation for rectal cancer.

Materials and methods

Retrospective multicentre study of rectal cancer patients treated with neoadjuvant chemoradiotherapy with capecitabine (cohort 1) or 5-fluororuracil (5-FU) (cohort 2); TNT with oxaliplatin-based regimens was allowed. The pathological response was considered a complete (ypCR) or complete + partial (ypCR + ypPR) according to American Joint Committee on Cancer. PPI use was considered at any time during the neoadjuvant period if concomitant to fluoropyrimidines.

Results

From January 2007 to November 2020, 251 patients received capecitabine and 196 5-FU. The rates of PPI use in cohorts 1 and 2 were 20.3% and 26.5%, respectively. TNT was offered to 18.3% in cohort 1. PPI use did not influence ypCR in cohort 1 (yes versus no: 29.4% versus 19.5%; p = 0.13) or 2 (yes versus no: 25.0% versus 26.4%; p = 1.0). Similar ypCR + ypPR were observed in both cohorts 1 (76.5% versus 72.0%; p = 0.60) and 2 (86.5% versus 76.4%; p = 0.16). PPI use was not associated with pathological response in multivariable analysis. PPI users experienced more grade 3 or higher diarrhoea and infections.

Conclusion

PPI concomitant to capecitabine/5-FU chemoradiation did not influence the pathological response in rectal cancer but was associated with more treatment-related adverse events.

Do proton pump inhibitors affect the effectiveness of chemotherapy in colorectal cancer patients? A systematic review with meta-analysis

Proton pump inhibitors (PPI), one of the most commonly prescribed medications, carry a myriad of adverse events. For colorectal cancer (CRC) patients, it still remains unclear whether the concurrent use of proton pump inhibitors (PPI) would negatively affect chemotherapy. PubMed, Medline, Embase, and Cochrane Library were searched from inception to 10 June 2022, to identify relevant studies involving CRC patients receiving chemotherapy and reporting comparative survival outcomes between PPI users and non-users. Meta-analyses were performed using random-effects models. We identified 16 studies involving 8,188 patients (PPI = 1,789; non-PPI = 6,329) receiving either capecitabine-based or fluorouracil-based regimens. The overall survival (HR, 1.02; 95% CI, 0.91 to 1.15; I² = 0%) and progression-free survival (HR, 1.15; 95% CI, 0.98 to 1.35; I² = 29%) were similar between PPI users and non-users in patients taking capecitabine-based regimens, with low statis-tical heterogeneity. Although the subgroup analysis indicated that early-stage cancer patients taking capecitabine monotherapy with concurrent PPI had a significantly higher disease progression rate (HR, 1.96; 95% CI, 1.21 to 3.16; I² = 0%) than those who did not use PPIs, both groups had comparable all-cause mortality (HR, 1.31; 95% CI, 0.75 to 2.29; I² = 0%). On the other hand, there was little difference in both OS and PFS in both early- and end-stage patients taking capecitabine combination therapy between PPI users and non-users. Conversely, the use of concomitant PPI in patients taking fluorouracil-based regimens contributed to a marginally significant higher all-cause mortality (HR, 1.18; 95% CI, 1.00 to 1.40; I² = 74%), but with high statistical heterogeneity. In conclusion, PPI has little survival influence on CRC patients treated with capecitabine-based regimens, especially in patients taking capecitabine combination therapy. Thus, it should be safe for clinicians to prescribe PPI in these patients. Although patients treated with fluorouracil-based regimens with concomitant PPI trended toward higher all-cause mortality, results were subject to considerable heterogeneity. Systematic Review Registration: identifier https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022338161.

Re-thinking the possible interaction between proton pump inhibitors and capecitabine

Proton Pump Inhibitors (PPI) rank within the top ten most prescribed medications in Europe and USA. A high frequency of PPI use has been reported amongst patients undergoing chemotherapy, to mitigate treatment-induced gastritis or gastro-oesophageal reflux. Several recent, mostly retrospective, observational studies have reported inferior survival outcomes among patients on capecitabine who concomitantly use PPI. Whilst this association is yet to be definitively established, given the prominence of capecitabine as an anti-cancer treatment with multiple indications, these reports have raised concern within the oncological community and drug regulatory bodies worldwide. Currently, the leading mechanism of interaction postulated in these reports has focussed on the pH altering effects of PPI and how this could diminish capecitabine absorption, leading to a decrease in its bioavailability. In this discourse, we endeavour to summarise plausible pharmacokinetic interactions between PPI and capecitabine. We provide a basis for our argument against the currently proposed mechanism of interaction. We also highlight the long-term effects of PPI on health outcomes, and how PPI use itself could lead to poorer outcomes, independent of capecitabine.

Association between the Co-administration of Histamine H2 Receptor Antagonists and the Effectiveness of Capecitabine in Patients with Colorectal Cancer: Propensity Score Analysis

Background: The association between the effectiveness of capecitabine and the concomitant administration of gastric acid suppressants remains controversial. We aimed to clarify whether the effectiveness of capecitabine is affected by the co-administration of histamine H₂ receptor antagonists (H₂RAs) in early-stage colorectal cancer (CRC) patients using real-world data. Methods: This multicenter, retrospective, observational study included consecutive patients with stage II-III CRC who received either capecitabine monotherapy or the CapeOX regimen (capecitabine and oxaliplatin) as adjuvant therapy between January 2009 and December 2014 in Japan. Relapse-free survival (RFS) and overall survival were estimated using the Kaplan-Meier method. Additionally, multivariable Cox proportional hazards model, propensity score adjustment, and inverse probability of treatment weighting analyses were performed. Results: In total, 552 patients were included in this study, of which 30 were co-administered H₂RAs. RFS at five years was 76.7% (95% confidence interval [CI]: 57.2-88.1%) and 79.8% (95% CI: 76.0-83.0%) in the H₂RA and non-H₂RA groups, respectively. Multivariable Cox proportional hazards model and propensity score-adjusted analyses showed that the co-administration of H₂RAs was associated with a poor RFS among those receiving capecitabine monotherapy (hazard ratio [HR], 2.01; 95% CI: 0.86-4.70 and HR, 1.81; 95% CI: 0.77-4.22, respectively). In contrast, these results were inconsistent with the group receiving the CapeOX regimen. Conclusions: The study findings suggest that the co-administration of H₂RAs may not reduce the effectiveness of capecitabine therapy in patients with early-stage CRC. To confirm this relationship, a prospective study with a pharmacokinetic approach is needed.

Proton pump inhibitors affect capecitabine efficacy in patients with stage II-III colorectal cancer: a multicenter retrospective study

The association between capecitabine efficacy and proton pump inhibitors (PPIs) is controversial. Here, we determined whether co-administration of PPIs affects the real-world effectiveness of capecitabine. This retrospective observational study included consecutive patients with stage II–III colorectal cancer (CRC) who received adjuvant capecitabine monotherapy or CapeOX (capecitabine and oxaliplatin) between January 2009 and December 2014 at nine participating institutions. The primary endpoint was the difference in relapse-free survival (RFS) between patients who received PPIs and those who did not and was estimated using the Kaplan–Meier method. Overall survival (OS) was the secondary endpoint. Multivariable analysis of RFS and OS was performed using a Cox proportional hazards model, propensity score adjustment, and inverse probability of treatment weighting (IPTW) analyses. Data from 606 patients were evaluated, 54 of whom had received a PPI. PPI-treated patients tended to have poorer RFS and OS than patients treated without PPIs. The hazard ratio for RFS with capecitabine monotherapy was 2.48 (95% confidence interval: 1.22–5.07). These results were consistent with sensitivity analyses performed using propensity score adjustment and IPTW methods. Co-administration of PPIs may reduce the effectiveness of capecitabine and negatively impact patients with stage II–III CRC.

Proton Pump Inhibitors and Cancer: Current State of Play

Background: Proton pump inhibitors (PPIs) are one of the most widely used drugs worldwide and are overprescribed in patients with cancer; there is increasing evidence of their effects on cancer development and survival. The objective of this narrative review is to comprehensively identify cancer medications that have clinically meaningful drug–drug interactions (DDIs) with PPIs, including loss of efficacy or adverse effects, and to explore the association between PPIs and cancer.

Methods: A PubMed search of English language studies published from 1 January 2016, to 1 June 2021 was conducted. The search terms included “proton pump inhibitors,” “cancer,” “chemotherapy,” “immunotherapy,” “hormonotherapies,” “targeted therapies,” “tyrosine kinase inhibitors,” and “gut microbiome”. Recent and relevant clinical trials, meta-analyses, and reviews were included.

Results: PPIs may have pro-tumor activity by increasing plasma gastrin levels or anti-tumor activity by inhibiting V-ATPases. However, their impact on cancer survival remains unclear. PPIs may decrease the efficacy of some antineoplastic agents through direct DDIs (e.g., some tyrosine kinase inhibitors, capecitabine, irinotecan, methotrexate). More complex DDIs seem to exist for immunotherapies with indirect interactions through the microbiome. PPIs worsen hypomagnesemia, bone loss, iron, and vitamin B12 deficiencies but may have a protective effect on the renal system.

Discussion/Conclusions: PPIs may interact with the cancer microbiome and the efficacy of various antineoplastic agents, although only a few DDIs involving PPIs are clinically significant. Further pharmaco-epidemiological studies are warranted, but physicians should be aware of the potential consequences of PPI use, which should be dose appropriate and prescribed according to guidelines.

Influence of the implementation of a multidisciplinary consultation program on adherence to the first ever course of oral antineoplastic treatment in patients with cancer

PURPOSE

To evaluate adherence (as measured by the medication possession ratio) to the first ever course of oral antineoplasic treatment in cancer patients before and after the implementation of a multidisciplinary consultation program (involving an oncologist, a pharmacist, and a nurse) and to investigate the program's impact on adverse events and drug-related problems.

PATIENTS AND METHODS

In a retrospective single-center study, we compared the medication possession ratio 2 months after treatment initiation in a control group (before multidisciplinary consultation program implementation) versus an interventional group (after multidisciplinary consultation program implementation).

RESULTS

Two months after oral antineoplasic treatment initiation, the mean ± standard deviation medication possession ratio did not differ significantly when comparing the interventional (multidisciplinary consultation program) group (n = 33; 0.99 ± 0.06) with the control group (n = 64; 0.94 ± 0.16) (p = 0.062). Patients in the multidisciplinary consultation program group had fewer adverse events in general (41, vs 109 in the control group; p = 0.048) and digestive adverse events in particular (6 vs 29, respectively; p = 0.007). A total of 53 and 40 drug-related problems were identified in the control and multidisciplinary consultation program groups, respectively (p = 0.074).

CONCLUSIONS

Implementation of an multidisciplinary consultation program was not associated with a significant difference in drug adherence (as assessed by the medication possession ratio), which was good before and after implementation. The multidisciplinary consultation program was associated with a lower incidence of adverse events.

Concomitant Use of Proton Pump Inhibitors With Capecitabine Based Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: Is it Safe?

AIM

Capecitabine (Cape) is routinely used for the neoadjuvant chemoradiation treatment (NACRT) of locally advanced rectal cancers (LARCs). Previous reports have suggested that the concomitant use of proton pump inhibitors (PPIs) may affect the efficacy of Cape, although the true effect of PPIs when used with Cape as a radiosensitizer for neoadjuvant radiation is unclear. The aim of our study was to evaluate the impact of concurrent PPI use along with fluorouracil (FU) and Cape based NACRT in terms of pathologic and oncological outcomes, in patients with LARC.

METHODS

LARC patients treated at our center with NACRT from 2010 to 2016 were identified. Postoperative pathology and follow-up outcomes were examined for any differences with relation to the use of PPIs concurrently with FU and Cape based NACRT and adjuvant chemotherapy regimens.

RESULTS

Three hundred four and 204 patients received treatment with FU and Cape based NACRT. No difference in pathologic complete response rate was noted between the 2 arms with the concurrent use of PPIs (25.8% and 25%, respectively, P=0.633); or with and without the use of PPIs in the Cape-NACRT arm specifically (20% and 20.7%, P=0.945). At a median follow-up of 5 years, no statistical difference in local or distant control was noted in the Cape-NACRT patients, with and without concomitant PPI use (P=0.411 and 0.264, respectively).Multivariate analysis showed no association of PPI use and NACRT with Cape, in terms of local control (hazard ratio=0.001, P=0.988) or overall survival (hazard ratio=1.179, confidence interval=0.249-5.579, P=0.835).

CONCLUSIONS

Our study revealed that there was no adverse pathologic or oncological outcome with the concurrent use of PPIs along with Cape-NACRT in the treatment of LARC. We report that it may be safe to use PPIs if essential, in this clinical setting, although it would be wise to exercise caution.

Controversial link between proton pump inhibitors and anticancer agents: review of the literature

Drug-drug interactions represent a topic of great interest, not only due to the risk of unexpected adverse events but also due to the possibility of altering the effectiveness of a specific treatment. Inappropriate or concomitant use of drugs can often lead to changes in the bioavailability of various compounds, resulting in pharmacokinetic alterations. A recent example is the concomitant administration of proton pump inhibitors (PPIs) and anticancer agents. PPIs are overused beyond their classic indications, resulting in a high risk of interactions with other drugs, such as anticancer agents, both PO and intravenous. However, the real clinical impact of concomitant acid suppression therapy and anticancer therapies remains controversial and is not yet fully understood. Certainly, the gut microbiota plays a key role in regulating the response of the immune system, and PPIs can significantly alter the gut microbiome, resulting in gut dysbiosis. Indeed, while the link sometimes appears to lead to negative outcomes, as in the case of immunotherapy, oral capecitabine, or tyrosine kinase inhibitors, in other cases, it seems to enhance the effectiveness of intravenous chemotherapy. In this review, I analyse the possible drug interactions between PPIs and the main classes of anticancer drugs.

Proton Pump Inhibitors and Survival in Patients With Colorectal Cancer Receiving Fluoropyrimidine-Based Chemotherapy

BACKGROUND

Concomitant use of proton pump inhibitors (PPIs) may negatively affect the efficacy of anticancer drugs such as fluoropyrimidines in patients with colorectal cancer (CRC). The primary objective of this study was to assess whether there is an association between concomitant PPI use and survival outcomes in patients with CRC treated with a fluoropyrimidine-based chemotherapy.

PATIENTS AND METHODS

A secondary analysis of 6 randomized controlled clinical trials in patients with advanced CRC was conducted using individual patient data through data-sharing platforms. The outcome measures were progression-free survival and overall survival in PPI users and nonusers. Subgroup analysis included the type of chemotherapy, capecitabine versus 5-FU, line of therapy, and addition of a vascular endothelial growth factor receptor inhibitor. Overall pooled hazard ratios (HRs) with 95% confidence intervals were calculated using a random effects model.

RESULTS

A total of 5,594 patients with advanced CRC across 6 trials and 11 trial arms were included; 902 patients were receiving a PPI at trial entry and initiation of chemotherapy. PPI use was significantly associated with worse overall survival (pooled HR, 1.20; 95% CI, 1.03-1.40; P=.02; I2 for heterogeneity = 69%) and progression-free survival (overall pooled HR, 1.20; 95% CI, 1.05-1.37; P=.009; I2 = 65%) after adjusting for clinical covariates. Furthermore, the association between concomitant PPI use and survival outcomes was similar across most treatment subgroups.

CONCLUSIONS

We speculate that alterations in the gut microbiome, altered immune milieu within the tumor, and interactions through transporters are potential mechanisms behind this association between PPI use and chemotherapy in patients with CRC, which warrant further study. Concomitant use of PPIs is associated with worse survival outcomes in patients with CRC treated with fluoropyrimidine-based chemotherapy. Clinicians should cautiously consider the concomitant use of PPIs in such patients.

Use of omeprazole, the proton pump inhibitor, as a potential therapy for the capecitabine-induced hand-foot syndrome

Hand-foot syndrome (HFS), also known as palmar-plantar erythrodysesthesia (PPE), is a major side effect of capecitabine. Although the pathogenesis of HFS remains unknown, some studies suggested a potential involvement of inflammation in its pathogenesis. Proton pump inhibitors (PPIs) have been reported to have anti-inflammatory effects. In this study, we investigated the ameliorative effects of omeprazole, a PPI on capecitabine-related HFS in mice model, and a real-world database. Repeated administration of capecitabine (200 mg/kg, p.o., five times a week for 3 weeks) increased fluid content, redness, and tumor necrosis factor (TNF)-α substance of the mice hind paw. Co-administration of omeprazole (20 mg/kg, p.o., at the same schedule) significantly inhibited these changes induced by capecitabine. Moreover, based on the clinical database analysis of the Food and Drug Administration Adverse Event Reporting System, the group that has used any PPIs had a lower reporting rate of capecitabine-related PPE than the group that has not used any PPIs. (6.25% vs. 8.31%, p < 0.0001, reporting odds ratio (ROR) 0.74, 95% confidence interval (CI) 0.65-0.83). Our results suggest that omeprazole may be a potential prophylactic agent for capecitabine-induced HFS.

Acid-suppressive agents and survival outcomes in patients with cancer: a systematic review and meta-analysis

BACKGROUND

Patients with cancer often receive acid-suppressive agents (ASAs) to treat common gastroesophageal reflux and peptic ulcer diseases. Our systematic review addresses the association between ASAs and survival outcomes in these patients.

METHODS

We searched MEDLINE, EMBASE, and Cochrane until December 2019, including randomized controlled trials (RCTs), quasi-RCTs, and observational studies concerning ASAs that reported progression-free survival (PFS) and/or overall survival (OS). We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) using the random-effects model, and assessed heterogeneity with I² statistic.

RESULTS

We included 45,626 patients from 7 RCTs and 18 observational studies, including esophageal/gastric, colorectal, pancreatic, lung, breast, prostate, kidney, and other cancers. Five studies showed that ASAs in lung cancer patients received tyrosine kinase inhibitors (TKIs) had significantly worse PFS (HR 1.64, 95% CI 1.14 - 2.37, I² = 57%) and OS (HR 1.13, 95% CI 1.05 - 1.21, I² = 0%) than nonusers. Each of five studies found no significant association between ASAs and OS in esophageal/gastric (HR 0.91, 95% CI 0.77 - 1.09, I² = 32%) or colorectal cancer patients (HR 1.33, 95% CI 0.96- 1.85, I² = 0%). ASAs were not significantly associated with an OS in patients with kidney cancer (HR 1.04, 95% CI 0.96 - 1.13, I² = 28%).

CONCLUSIONS

Meta-analysis showed that ASAs significantly associated with an increased mortality risk in lung cancer patients treated TKIs, but not in patients with esophageal/gastric, colorectal, or kidney cancer. Until further studies confirm these results, caution should be used when administering ASAs and TKIs to patients with lung cancer.

Efficacy of capecitabine when used concomitantly with proton pump inhibitors in cancer patients: a systematic review

BACKGROUND

Capectiabine is an oral antineoplastic drug used in multiple malignancies. Proton pump inhibitors (PPI) have been proven to interact with other oral antineoplastic agents. In this systematic review we will summarize the clinical evidence on the efficacy of capecitabine when used concomitantly with PPI.

MATERIALS AND METHODS

We performed a systematic literature search on the main databases up to November 2019.

RESULTS

Nine studies met our inclusion criteria: 8 retrospective studies and 1 phase II clinical trial. Patients with colorectal, breast and gastroesophageal were represented. Four out of the 9 studies reported a shorter efficacy outcome in uni- or multivariate analysis when capecitabine was taken concomitantly with PPI than alone.

CONCLUSIONS

Up to date, the clinical evidence reported on the use of capecitabine concomitantly with PPI is scarce and shows conflicting results. While awaiting further data, avoiding misuse of PPI in cancer patients taking capecitabine is recommended.