Emerging hazard effects of proton pump inhibitor on the risk of colorectal cancer in low-risk populations: A Korean nationwide prospective cohort study

Proton Pump Inhibitors and Oral-Gut Microbiota: From Mechanism to Clinical Significance

Proton pump inhibitors (PPIs) are some of the most commonly prescribed drugs worldwide, but there are increasing concerns about digestive complications linked to PPIs. Next-generation sequencing studies have suggested that PPIs can significantly affect the composition of the gut microbiota, which in turn may substantially contribute to the development of these complications. Recently, emerging evidence has suggested that the translocation of oral microbes into the gut may be the primary mechanism underlying the alterations in the gut microbiota induced by PPIs in the presence of gastric acid suppression and impaired oral-gut barrier function. Moreover, the significance of oral-gut microbial translocation in health and disease conditions has gained increasing recognition. Consequently, it is imperative to enhance our understanding of the functions of the oral-gut microbiota axis in digestive disorders associated with PPI therapies. This review aims to summarize current research findings and further elucidate the contribution of the oral-gut microbiota to the pathogenesis of PPI-related digestive diseases. We aim to provide a theoretical foundation for future therapeutic and preventive strategies targeting PPI-related digestive complications through modulation of the oral-gut microbiota.

The association between proton-pump inhibitor use and recurrence of hepatocellular carcinoma after hepatectomy

BACKGROUND AND AIM

The association between long-term proton-pump inhibitors (PPIs) use and malignancies had long been discussed, but it still lacks consensus. Our study investigated the association between PPI use and hepatocellular carcinoma (HCC) recurrence following curative surgery.

METHODS

We retrospectively enrolled 6037 patients with HCC who underwent hepatectomy. Patients were divided into four groups according to their PPI usage. (non-users: < 28 cumulative defined daily dose [cDDD]; short-term users: 28-89 cDDD; mid-term users: 90-179 cDDD, and long-term users: ≥ 180 cDDD, respectively). Recurrence-free survival (RFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazard models.

RESULTS

Among the 6037 HCC patients, 2043 (33.84%) were PPI users. PPI users demonstrated better median RFS (3.10 years, interquartile range [IQR] 1.49-5.01) compared with non-users (2.73 years, IQR 1.20-4.74; with an adjusted hazard ratio [aHR] of 0.57, 95% confidence interval [CI] 0.44-0.74, P < 0.001). When considering the cumulative dosage of PPI, only long-term PPI users had significant lower risk of HCC recurrence than non-PPI group (adj-HR: 0.50; 95% CI: 0.35-0.70; P < 0.001). Moreover, the impact of long-term PPIs use on improving RFS was significant in most of the subgroup analysis, except in patients with advanced tumor stages, with non-cirrhosis, or with a history of chronic kidney disease. However, there were no significant differences in median OS between PPI users and non-users (4.23 years, IQR 2.73-5.86 vs 4.04 years, IQR 2.51-5.82, P = 0.369).

CONCLUSION

Long-term PPI use (≥ 180 cDDD) may be associated with a better RFS in HCC patients after hepatectomy.

Maintenance proton pump inhibitor use and risk of colorectal cancer: a Swedish retrospective cohort study

OBJECTIVES

We aimed to evaluate the risk of colorectal adenocarcinoma (CRA) associated with long-term use of proton pump inhibitors (PPIs) in a large nationwide cohort.

DESIGN

Retrospective cohort study.

SETTING

This research was conducted at the national level, encompassing the entire population of Sweden.

PARTICIPANTS

This study utilised Swedish national registries to identify all adults who had ≥180 days of cumulative PPI use between July 2005 and December 2012, excluding participants who were followed up for less than 1 year. A total of 754 118 maintenance PPI users were included, with a maximum follow-up of 7.5 years.

INTERVENTIONS

Maintenance PPI use (cumulative≥180 days), with a comparator of maintenance histamine-2 receptor antagonist (H2RA) use.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was the risk of CRA, presented as standardised incidence ratios (SIRs) with 95% confidence intervals (CIs). Subgroup analyses were performed to explore the impact of indications, tumour locations, tumour stages and the duration of follow-up. A multivariable Poisson regression model was fitted to estimate the incidence rate ratios (IRRs) and 95% CIs of PPI versus H2RA use.

RESULTS

Maintenance PPI users exhibited a slightly elevated risk of CRA compared to the general population (SIR 1.10, 95% CI=1.06 to 1.13) for both men and women. Individuals aged 18-39 (SIR 2.79, 95% CI=1.62 to 4.47) and 40-49 (SIR 2.02, 95% CI=1.65 to 2.45) had significantly higher risks than the general population. Right-sided CRA showed a higher risk compared to the general population (SIR 1.26, 95% CI=1.20 to 1.32). There was no significant difference in the risk of CRA between maintenance PPI users and maintenance H2RA users (IRR 1.05, 95% CI=0.87 to 1.27, p<0.05).

CONCLUSIONS

Maintenance PPI use may be associated with an increased risk of CRA, but a prolonged observation time is needed.

Proton pump inhibitors and risk of gastrointestinal cancer: A meta‑analysis of cohort studies

Although proton pump inhibitors (PPIs) are widely used in the treatment of various acid-related disorders, observational studies have raised concern about an association between PPI use and the risk of gastrointestinal cancer. The present study aimed to investigate the association between them using a meta-analysis of cohort studies. PubMed and Excerpta Medica dataBASE were searched from inception to December 2022 to identify relevant cohort studies. The primary outcome was the risk of gastrointestinal cancer among PPI users, expressed as a pooled odds ratio (OR), relative risk (RR) or hazard ratio (HR) and its 95% CI based on a random-effects model. A total of 25 cohort studies from 23 articles were included in the final analysis. In the meta-analysis of all studies, an increased risk of gastrointestinal cancer following the use of PPIs was observed (OR/RR/HR, 2.09; 95% CI, 1.78-2.46). Subgroup analyses by type of cancer also revealed an association between PPI use and the risk of esophageal, gastric, liver and pancreatic cancer, whereas there was no association for colorectal cancer. The increased risk of gastrointestinal cancer was also observed in individuals who had used PPIs for <1 year (OR/RR/HR, 5.23; 95% CI, 2.96-9.24) as well as individuals who had used PPIs for up to 3 years. The present meta-analysis revealed that the use of PPIs was associated with an increased risk of gastrointestinal cancer.

Proton Pump Inhibitors and Likelihood of Colorectal Cancer in the Korean Population: Insights from a Nested Case-Control Study Using National Health Insurance Data

The potential connection between proton pump inhibitors (PPIs) and colorectal cancer (CRC) risk remains unclear, with specific ethnic genetic backgrounds playing a role in PPI-induced adverse effects. In this nested case-control study, we investigated the risk of CRC in relation to preceding PPI use and the duration of use using data from the Korean National Health Insurance Service-National Sample Cohort database, including 9374 incident CRC patients and 37,496 controls. To assess the impact of preceding PPI exposure (past vs. current) and use duration (days: <30, 30-90, and ≥90) on incident CRC, we conducted propensity score overlap-weighted multivariate logistic regression analyses, adjusted for confounding factors. Our findings revealed that past and current PPI users had an increased likelihood of developing CRC. Regardless of duration, individuals who used PPIs also had higher odds of developing CRC. Subgroup analyses revealed that CRC occurrence increased independent of history or duration of prior PPI use, consistent across various factors such as age, sex, income level, and residential area. These findings suggest that PPI use, regardless of past or present use and duration of use, may be related to an increased risk of developing CRC in the Korean population.

Meta-analysis of proton pump inhibitor use and the risk of developing gastric cancer or colorectal cancer

To evaluate the relationship between the use of proton pump inhibitors (PPI) and the risk of gastric cancer and colorectal cancer by using meta-analysis. Computer search PUBMED, EMBASE, Cochrane Library, CNKI and Wanfang database to obtain relevant literature on the use of PPI and the risk of gastric cancer and colorectal cancer, extract relevant data, and use Stata14.0 for Meta-analysis. A total of 24 articles were included, including 12 articles for gastric cancer and 12 articles for colorectal cancer. A total of 5 313 749 persons were included in the study and analysis. Meta-analysis results showed that the risk of gastric cancer in PPI users was significantly increased [risk ratio (RR) = 2.04, 95% confidence interval (CI) (1.33-2.75)], and the regional subgroup analysis results showed that in Europe [RR = 2.01, 95% CI (0.92, 3.09), P < 0.05] and Asia [RR = 2.15, 95% CI (1.16, 3.14), P < 0.05] This risk is higher, and Asia is higher than Europe. The risk of colorectal cancer is slightly increased [RR = 1. 22, 95% CI (1.03, 1.40, P < 0.05], and the regional subgroup analysis results show that in Europe [RR = 1.05 95% CI (0.98, 1.12), P < 0.05] and Asia [RR = 1.18, 95% CI (1.10, 1.27), P < 0.05]. This risk is low, but Asia is higher than Europe. The use of PPI significantly increases gastric cancer However, the risk of colorectal cancer is not significantly increased. The risk of gastric cancer and colorectal cancer in the population using PPI in Asia is higher than that in Europe.

Operational Definitions of Colorectal Cancer in the Korean National Health Insurance Database

OBJECTIVES

We reviewed the operational definitions of colorectal cancer (CRC) from studies using the Korean National Health Insurance Service (NHIS) and compared CRC incidence derived from the commonly used operational definitions in the literature with the statistics reported by the Korea Central Cancer Registry (KCCR).

METHODS

We searched the MEDLINE and KoreaMed databases to identify studies containing operational definitions of CRC, published until January 15, 2021. All pertinent data concerning the study period, the utilized database, and the outcome variable were extracted. Within the NHIS-National Sample Cohort, age-standardized incidence rates (ASRs) of CRC were calculated for each operational definition found in the literature between 2005 and 2019. These rates were then compared with ASRs from the KCCR.

RESULTS

From the 62 eligible studies, 9 operational definitions for CRC were identified. The most commonly used operational definition was "C18-C20" (n=20), followed by "C18-C20 with claim code for treatment" (n=3) and "C18-C20 with V193 (code for registered cancer patients' payment deduction)" (n=3). The ASRs reported using these operational definitions were lower than the ASRs from KCCR, except for "C18-C20 used as the main diagnosis." The smallest difference in ASRs was observed for "C18-C20," followed by "C18- C20 with V193," and "C18-C20 with claim code for hospitalization or code for treatment."

CONCLUSIONS

In defining CRC patients utilizing the NHIS database, the ASR derived through the operational definition of "C18-C20 as the main diagnosis" was comparable to the ASR from the KCCR. Depending on the study hypothesis, operational definitions using treatment codes may be utilized.

Association of proton pump inhibitors with gastric and colorectal cancer risk: A systematic review and meta-analysis

Background: Proton pump inhibitors (PPI) are generally considered to be one of the well-established prescription drug classes and are commonly used to treat most acid-related diseases. However, a growing body of literature showing an association between gastric and colorectal cancer risk and PPI use continues to raise concerns about the safety of PPI use. Therefore, we aimed to investigate the association between proton pump inhibitor use and risk of gastric and colorectal cancer.

Methods: We collected relevant articles using PubMed, Embase, Web of Science and Cochrane library from 1 January 1990 to 21 March 2022. The pooled effect sizes were calculated based on the random-effects model. The study was registered with PROSPERO (CRD42022351332).

Results: A total of 24 studies (n = 8,066,349) were included in the final analysis in the screening articles. Compared with non-PPI users, PPI users had a significantly higher risk of gastric cancer (RR = 1.82, 95% CI: 1.46–2.29), but not colorectal cancer (RR = 1.22, 95% CI: 0.95–1.55). Subgroup analysis showed that there was a significant positive correlation between the use of PPI and the risk of non-cardiac cancer (RR = 2.75, 95% CI: 2.09–3.62). There was a significant trend between the duration dependent effect of PPI use and the risk of gastric cancer (&lt;1 year RR = 1.56, 95% CI: 1.30–1.86; 1–3 years RR = 1.75, 95% CI: 1.28–2.37; &gt;3 years RR = 2.32, 95% CI: 1.15–4.66), but not colorectal cancer (≤1 year RR = 1.00, 95% CI: 0.78–1.28; &gt;1 year RR = 1.18, 95% CI: 0.91–1.54; ≥5 years RR = 1.06, 95% CI: 0.95–1.17).

Conclusion: We found that PPI use increased gastric cancer risk, but not colorectal cancer risk. This result may be biased due to confounding factors. More prospective studies are needed to further validate and support our findings.

Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022351332], identifier [CRD42022351332].

Proton Pump Inhibitors and Cancer Risk: An Umbrella Review and Meta-analysis of Observational Studies

OBJECTIVES

Increasing evidence suggested that proton pump inhibitors (PPIs) use might affect the development of cancers, but previous conclusions remain controversial. Therefore, an umbrella review was performed to clarify the associations between PPIs and various types of cancer by summarizing the existing meta-analyses and systematic reviews.

METHODS

We searched PubMed, Cochrane Library, Embase, CNKI, Wanfang, and VIP database up to June 2022 for eligible meta-analyses or systematic reviews. The summary effect size, 95% CI, heterogeneity, small study effect, and 95% prediction interval were considered in the present study. A Measurement Tool to Assess Systematic Review 2 and grading of recommendation, assessment, development, and evaluation were used to assess methodological quality and evidence.

RESULTS

The umbrella review included 21 meta-analyses containing 65 studies and 10 cancer types with 6.8 million subjects. The results showed that PPI use was significantly associated with increased risks of certain types of cancer, including gastric cancer (odds ratio [OR]: 2.07; 95% CI, 1.30 to 3.29), pancreatic cancer (OR: 1.73; 95% CI, 1.23 to 2.44), colorectal cancer (OR: 1.84; 95% CI, 1.26 to 2.67), and liver cancer (OR: 1.80; 95% CI, 1.27 to 2.54), but was not associated with esophageal cancer. In addition, PPI use was associated with decreased risk of breast cancer (OR: 0.69; 95% CI, 0.50 to 0.96).

CONCLUSIONS

These findings suggested that clinicians should pay more attention to the occurrence of gastric cancer, pancreatic cancer, colorectal cancer, and liver cancer in patients who used PPIs, and PPI prescription should be written only when an accurate specific diagnosis has been made. Furthermore, additional PPIs to the treatment regimen may be benefit for women with a higher-than-average risk of breast cancer.

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.

Proton Pump Inhibitor Use and Obesity-Associated Cancer in the Women's Health Initiative

Proton pump inhibitors (PPIs) have off-target activity on fatty acid synthase (FASN), a critical enzyme in energy balance and cancer growth. We evaluated risk of common obesity-related cancers: breast, colorectal (CRC), and endometrial, with use of PPI and histamine-2 receptor antagonists (H2RA) in 124,931 postmenopausal women enrolled in the Women's Health Initiative. Incident cancer cases were physician-adjudicated. Cox proportional hazards models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI) for cancer incidence after year 3. There were 7956 PPI ever users and 9398 H2RA only users. Ever use of either PPI or H2RA was not associated with risk of breast cancer (n = 9186) nor risk of endometrial cancer (n = 1231). The risk of CRC (n = 2280) was significantly lower in PPI users (HR = 0.75, 95% CI = 0.61-0.92), but not in H2RA users (HR = 1.13, 95% CI = 0.97-1.31). The association of PPI use with CRC was apparent regardless of BMI or NSAID use, and was stronger with longer PPI duration (p = 0.006) and potency (p = 0.005). The findings that PPI use, but not H2RA use, demonstrate an inverse dose-response relationship with risk of CRC is consistent with preclinical data showing FASN inhibition prevents colon cancer progression and supports a role of PPI in CRC prevention.

Association between Proton Pump Inhibitor Use and Risk of Hepatocellular Carcinoma: A Korean Nationally Representative Cohort Study

(1) Background: The association between proton pump inhibitor (PPI) use and hepatocellular carcinoma (HCC) has been controversial, especially in the general population. We aimed to determine the impact of PPI on HCC risk in participants without liver cirrhosis or chronic hepatitis virus infection. (2) Methods: We assessed 406,057 participants from the Korean National Health Insurance Service database who underwent health screening from 2003 to 2006. We evaluated exposure to PPI before the index date using a standardized daily defined dose (DDD) system. The association of proton pump inhibitor use with the risk of HCC was evaluated using multivariable-adjusted Cox proportional hazards regression. (3) Results: Compared with non-users, PPI use was not associated with the HCC risk in low (<30 DDDs; aHR, 1.07; 95% CI, 0.91−1.27), intermediate (30 ≤ PPI < 60 DDDs; aHR, 0.96; 95% CI, 0.73−1.26), and high (≥60 DDDs; aHR, 0.86; 95% CI, 0.63−1.17) PPI groups in the final adjustment model. In addition, risks of cirrhosis-associated HCC and non-cirrhosis-associated HCC were not significantly associated with PPI use. The results remained consistent after excluding events that occurred within 1, 2, and 3 years to exclude pre-existing conditions that may be associated with the development of HCC. We also found no PPI-associated increase in HCC risk among the selected population, such as those with obesity, older age, and chronic liver diseases. (4) Conclusions: PPI use may not be associated with HCC risk regardless of the amount. We call for future studies conducted in other regions to generalize our findings.

Anticoagulant drugs with or without proton pump inhibitor and colorectal cancer risk: a population-based, case-control study

Background

Low-dose aspirin and clopidogrel have demonstrated potential chemoprevention for colorectal cancer (CRC). Proton-pump inhibitors (PPI) are commonly prescribed with anticoagulation drugs, but the relationship between PPI and CRC is unclear. Moreover, evidence of CRC risk under direct oral anticoagulant (DOAC) is limited. This study aimed to investigate the effects of anticoagulation drugs combined with or without PPI on the risks of CRC in Taiwan.

Methods

A retrospective case–control study of 1,024,227 cases based on the Chang Gung Research Database from 2010 to 2017 was performed. Clinical characteristics, indications, duration of anticoagulation and PPI use, and CRC occurrence data were collected. Logistic regression was employed to adjust for known confounders of CRC risk.

Results

Monotherapy of clopidogrel decreased the risk of CRC (AOR 0.70; 95% CI 0.60–0.83), while no protective effect was observed in aspirin alone or aspirin plus clopidogrel. DOAC did not affect CRC significantly. The risk of CRC increased in patients with PPI (AOR 1.38; 95% CI 1.28–1.49) and PPI plus DOAC (OR 3.91; 95% CI 1.49–10.27), while PPI plus aspirin decreased the risk of CRC (OR 0.48; 95% CI 0.32–0.73). PPI plus clopidogrel showed no significant effect on the CRC.

Conclusion

This study suggests clopidogrel alone and PPI plus aspirin offer a preventative benefit against CRC in the Taiwanese population studied. The same effect was not observed in DOAC. Moreover, a significant increase in CRC was observed in patients on PPI monotherapy and PPI plus DOAC, suggesting a possible risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02314-w.

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.

Proton pump inhibitors and risk of colorectal cancer

OBJECTIVE

To determine whether proton pump inhibitors (PPIs) are associated with an increased risk of colorectal cancer, compared with histamine-2 receptor antagonists (H2RAs).

DESIGN

The United Kingdom Clinical Practice Research Datalink was used to identify initiators of PPIs and H2RA from 1990 to 2018, with follow-up until 2019. Cox proportional hazards models were fit to estimate marginal HRs and 95% CIs of colorectal cancer. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Prespecified secondary analyses assessed associations with cumulative duration, cumulative dose and time since treatment initiation. The number needed to harm was calculated at five and 10 years of follow-up.

RESULTS

The cohort included 1 293 749 and 292 387 initiators of PPIs and H2RAs, respectively, followed for a median duration of 4.9 years. While the use of PPIs was not associated with an overall increased risk of colorectal cancer (HR: 1.02, 95% CI 0.92 to 1.14), HRs increased with cumulative duration of PPI use (<2 years, HR: 0.93, 95% CI 0.83 to 1.04; 2-4 years, HR: 1.45, 95% CI 1.28 to 1.60; ≥4 years, HR: 1.60, 95% CI 1.42 to 1.80). Similar patterns were observed with cumulative dose and time since treatment initiation. The number needed to harm was 5343 and 792 for five and 10 years of follow-up, respectively.

CONCLUSION

While any use of PPIs was not associated with an increased risk of colorectal cancer compared with H2RAs, prolonged use may be associated with a modest increased risk of this malignancy.

Proton pump inhibitors and colorectal cancer: A systematic review

BACKGROUND

The use of proton pump inhibitors (PPI) is common worldwide, with reports suggesting that they may be overused. Several studies have found that PPI may affect colorectal cancer (CRC) risk.

AIM

To summarize current knowledge on the relationship between PPI and CRC from basic research, epidemiological and clinical studies.

METHODS

This systematic review was based on the patients, interventions, comparisons, outcome models and performed according to PRISMA guidelines. MEDLINE, EMBASE, Scopus, and Web of Science databases were searched from inception until May 17, 2021. The initial search returned 2591 articles, of which, 28 studies met the inclusion criteria for this review. The studies were categorized as basic research studies (n = 12), epidemiological studies (n = 11), and CRC treatment studies (n = 5). The quality of the included studies was assessed using the Newcastle-Ottawa Scale or Cochrane Risk of Bias 2.0 tool depending on the study design.

RESULTS

Data from basic research indicates that PPI do not stimulate CRC development via the trophic effect of gastrin but instead may paradoxically inhibit it. These studies also suggest that PPI may have properties beneficial for CRC treatment. PPI appear to have anti-tumor properties (omeprazole, pantoprazole), and are potential T lymphokine-activated killer cell-originated protein kinase inhibitors (pantoprazole, ilaprazole), and chemosensitizing agents (pantoprazole). However, these mechanisms have not been confirmed in human trials. Current epidemiological studies suggest that there is no causal association between PPI use and increased CRC risk. Treatment studies show that concomitant PPI and capecitabine use may reduce the efficacy of chemotherapy resulting in poorer oncological outcomes, while also suggesting that pantoprazole may have a chemosensitizing effect with the fluorouracil, leucovorin, oxaliplatin (FOLFOX) regimen.

CONCLUSION

An unexpected inhibitory effect of PPI on CRC carcinogenesis by way of several potential mechanisms is noted. This review identifies that different PPI agents may have differential effects on CRC treatment, with practical implications. Prospective studies are warranted to delineate this relationship and assess the role of individual PPI agents.

Comprehensive analysis of proton pump inhibitors and risk of digestive tract cancers

BACKGROUND

For the past two decades, dispute on whether proton pump inhibitor (PPI) leads to digestive tract cancer remains, and emerging studies in recent years still demonstrate inconsistent results, which continues to perpetuate concerns over the safety of PPI use. We performed a systematic review and meta-analysis, with comprehensive evaluation by Bradford Hill criteria of causation, to assess the effect of PPI use on digestive tract cancers.

METHODS

Medline, Embase and Web of Science databases were searched for observational studies published up to 15th January 2021. Pooled relative risks (RRs) were estimated via random effects models. Cumulative defined daily dose- and duration-risk relationships using restricted cubic spline and fractional polynomial models were investigated. Bradford Hill criteria were applied to evaluate causation. PROSPERO Registration: CRD42020211103.

RESULTS

Thirty-two publications containing 4,355,254 participants were included. PPI use is associated with an increased risk of overall digestive tract cancers (RR = 1.63, 95% confidence interval (CI) 1.33 to 2.00). PPI use is correlated with increased risks of gastric cancer (RR = 1.78, 95% CI 1.38 to 2.31), pancreatic cancer (RR = 1.72, 95% CI 1.05 to 2.82) and liver cancer (RR = 1.62, 95% CI 1.04 to 2.52), but not of esophageal cancer (RR = 2.06, 95% CI 0.65 to 6.57) and colorectal cancer (RR = 1.24, 95% CI 0.93 to 1.66). The association between PPI and digestive tract cancers is stronger in people with minimal exposure. When cumulative defined daily dose or duration increases, the risks decline and become non-significant. Evaluation by Bradford Hill criteria indicates weak evidence of causation.

CONCLUSIONS

A causal relationship between PPI use and digestive tract cancers is not supported by the evidence in the current review. Concerns over carcinogenic side-effects of PPI might be unfounded.

Proton pump inhibitors and survival in patients with colorectal cancer: a Swedish population-based cohort study

BACKGROUND

Proton pump inhibitors (PPIs) are associated with microbiome changes of the gut, which in turn may affect the progression of colorectal cancer (CRC). This study aims to assess the associations between PPI use and all-cause and CRC-specific mortality.

METHODS

We selected all patients registered in the Swedish Prescribed Drug Registry who were diagnosed with CRC between 2006 and 2012 (N = 32,411, 54.9% PPI users) and subsequently followed them through register linkage to the Swedish Causes of Death Registry until December 2013. PPI users were patients with ≥1 post-diagnosis PPI dispensation. Time-dependent Cox-regression models were performed with PPI use as time-varying exposure.

RESULTS

Overall 4746 (14.0%) patients died, with an aHR of 1.38 (95% CI 1.32-1.44) for all-cause mortality comparing PPI users with PPI nonusers. Higher-magnitude associations were observed among male, cancer stage 0-I, rectal cancer and patients receiving CRC surgery. The PPI-all-cause mortality association was also more pronounced comparing new users to non-users (aHR = 1.47, 95%CI 1.40-1.55) than comparing continuous users to non-users (aHR = 1.32, 95%CI 1.24-1.39). The risk estimates for CRC-specific mortality comparing PPI users to PPI nonusers were similar to those for all-cause mortality.

CONCLUSION

PPI use after the CRC diagnosis was associated with increased all-cause and CRC-specific mortality.

Association between the chronic use of gastric acid suppressants and high-risk colorectal polyps

Background and Aim

Although gastric acid suppressants such as proton pump inhibitors (PPIs) and histamine‐2 receptor antagonists (H2RAs) are considered safe, the consequences of hypochlorhydria and hypergastrinemia caused by chronic use are unclear. This study aimed to investigate the association between the chronic use of gastric acid suppressants and high‐risk colorectal polyps, focusing on polyp size.

Methods

A population‐based, nested case–control study was conducted using data from the Japanese Diagnosis Procedure Combination database between 2014 and 2019. Cumulative PPI or H2RA use prior to polypectomy was evaluated during the study period. Endoscopic polypectomy was categorized as polypectomy <2 cm, polypectomy ≥2 cm, and endoscopic submucosal dissection. Baseline characteristics were compared between the high‐risk (≥2 cm polyps or polyps treated by endoscopic submucosal dissection) and low‐risk (<2 cm polyps) endoscopic polypectomy groups. We calculated adjusted odds ratios (ORs) using multivariable logistic regression analysis.

Results

Of 27 694 patients who underwent endoscopic polypectomy, 2518 were treated with PPIs or H2RAs for >1 year prior to polypectomy. After adjusting for age, gender, and other confounders, a higher prevalence of high‐risk colorectal polyps was noted with PPI (OR: 2.67; 95% confidence interval: 2.37–3.01) and H2RA (OR: 1.86; 95% confidence interval: 1.52–2.26) use. Longer PPI or H2RA use was associated with increased risks of high‐risk colorectal polyps (P for trend <0.001). The highest OR (3.17) was observed among patients who received PPIs for ≥3 years.

Conclusion

Chronic use of PPIs and H2RAs may be associated with high‐risk colorectal polyps. Requirements for long‐term gastric acid suppressant use should be reevaluated.

Proton pump inhibitors and the risk of colorectal cancer: a systematic review and meta-analysis of observational studies

PURPOSE

The increased risk of colorectal cancer (CRC) associated with long-term use of proton pump inhibitors (PPIs) has attracted considerable attention; however, the conclusions of studies evaluating this correlation are inconsistent or even controversial. Therefore, we conducted a systematic review and meta-analysis to determine the association of PPI use with the risk of CRC.

METHODS

A systematic literature search was conducted in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) for the associations between PPI use and the risk of CRC were estimated with a fixed-effects or random-effects model.

RESULTS

We identified and included 9 observational studies (3 cohort studies and 6 case-control studies) comprising 1,036,438 participants. Overall, there was no statistically significant association between PPI use and the risk of CRC (pooled OR 1.26, 95% CI: 0.90-1.73; p = 0.166) when PPI exposure was assessed as a binary variable. However, a weak association between long-term use of PPIs and CRC was demonstrated (pooled OR 1.19, 95% CI: 1.09-1.31; p < 0.001) when the cumulative duration of PPI exposure was confined to > 5 years.

CONCLUSIONS

Although the present meta-analysis suggests a weak association between long-term use (> 5 years) of PPIs and CRC, there is not enough statistical power to refute or confirm an association between the use of PPIs and CRC. More high-quality prospective cohort studies are needed to assess this correlation.

Acid-suppressive medications and risk of colorectal cancer: results from three large prospective cohort studies

BACKGROUND

Despite several plausible biological mechanisms linking proton pump inhibitors (PPIs) and H2 receptor antagonists (H2RAs) with colorectal tumorigenesis, their association with risk of colorectal cancer (CRC) has not been adequately assessed in prospective epidemiological studies.

METHODS

We evaluated the association of acid-suppressive medication use with CRC risk among 175,871 (PPI) and 208,831 (H2RA) participants from three large prospective cohort studies. Medication use was assessed at baseline and updated biennially. The association was evaluated using multivariate Cox proportional hazards regression models.

RESULTS

There was no significant association between baseline PPI use (hazard ratio (HR) = 0.89, 95% confidence interval (CI), 0.71-1.12) or PPI use after a lag of 8-10 years (HR = 1.12, 95% CI, 0.78-1.59) with CRC risk. We observed no significant association between H2RA use after a lag of 8-10 years and CRC risk (HR = 1.02, 95% CI, 0.81-1.28), while risk was lower for participants with baseline H2RA use (HR = 0.76, 95% CI, 0.60-0.95). Duration of PPI use or H2RA use was not associated with CRC risk (P-trend = 0.21 and 0.95, respectively).

CONCLUSIONS

Among participants from three large prospective cohorts, use of PPI or H2RA was not associated with higher risk of colorectal cancer.

The deleterious association between proton pump inhibitors and prostate cancer-specific mortality - a population-based cohort study

BACKGROUND

Proton pump inhibitors (PPIs) are commonly prescribed medications that have been shown to have contradicting effects on cancer. We aimed to investigate the effect of pantoprazole and other PPIs on prostate cancer (PCa) specific mortality (PCSM), use of androgen deprivation therapy (ADT), and PCa diagnosis using a large Canadian population-based cohort.

METHODS

We identified 21,512 men aged ≥ 66, with a history of a single negative prostate biopsy and no previous use of any of the analyzed medications between 1994 and 2016. Multivariable Cox regression models with time-dependent covariates were used to assess the associations of PPIs with PCa outcomes. All models included other medications with a putative chemopreventative effect on PCa-outcomes, and were adjusted for age, rurality, comorbidity, and study inclusion year.

RESULTS

Over a mean follow-up of 8.06 years (SD 5.44 years), 10,999 patients (51.1%) used a PPI, 5187 patients (24.1%) had PCa, 2043 patients (9.5%) were treated with ADT, and 805 patients (3.7%) died from PCa. For every 6 months of cumulative use, pantoprazole was associated with a 3.0% (95% CI 0.3-6.0%) increased rate of ADT use, while any use of other PPIs was associated with a 39.0% (95% CI 18.0-64.0%) increased risk of PCSM. No association was found with PCa diagnosis.

CONCLUSIONS

Upon validation of the potentially negative association of PPIs with PCa, PPI use may need to be reassessed in PCa patients.

The association between acid-suppressive agent use and the risk of cancer: a systematic review and meta-analysis

BACKGROUND

Acid-suppressive agents (ASAs) may be associated with cancer; previous studies reported that the risk of cancer with acid suppressants has differed depending on the site of cancer. Here, we conducted a systematic review and meta-analysis of the association between ASA use and the type of cancer risk.

METHODS

MEDLINE, EMBASE, and Cochrane library databases were searched for publications up to the end of September 2019 for MeSH terms and text words related to cancer and ASAs. Studies on the association between ASAs and cancer risk, which included a control group and reported the relative risk of cancer, were included. The inverse-variance random effect model was used to estimate the pooled relative risk (RR) and 95% confidence interval (CI), and subgroup analysis for type of acid suppressants, drug uptake duration, and cumulative doses was performed. Heterogeneity was assessed using the I² test and Q statistic.

RESULTS

Thirty-nine cohort and case-control studies were included. ASA use was found to be significantly associated with a 46% higher risk of gastric cancer (RR, 1.46; 95% CI, 1.18-1.80) and a 53% higher risk of liver cancer (RR, 1.53; 95% CI, 1.31-1.78) compared with nonuse; however, there was no significant association for esophageal, colorectal, pancreatic, lung, breast, prostate, and kidney cancer; melanoma; and lymphoma.

CONCLUSIONS

ASAs were significantly associated with an increased risk of gastric and liver cancer; therefore, special attention of ASA use considering the potential risk of gastric and liver cancer is needed.

Proton Pump Inhibitor Use and Risk of Gastric, Colorectal, Liver, and Pancreatic Cancers in a Community-Based Population

INTRODUCTION

Proton pump inhibitors (PPIs) are commonly used for gastrointestinal disorders; given they increase the systemic levels of gastrin, a trophic hormone, there is a concern about their carcinogenicity. This study evaluated the association between PPI use and gastrointestinal cancers.

METHODS

We performed a nested case-control study in a large, community-based integrated healthcare setting. Cases were adults with gastric (n = 1,233), colorectal (n = 18,595), liver (n = 2,329), or pancreatic cancers (n = 567). Each case was matched with up to 10 controls by age, sex, race/ethnicity, medical facility, and enrollment duration. The primary exposure was defined as ≥2-year cumulative PPI supply. Data were obtained from pharmacy, cancer registry, and electronic medical record databases. Associations were evaluated using conditional logistic regression and adjusted for multiple confounders. We also evaluated the cancer risks separately by PPI dose, duration of use, and dose and duration.

RESULTS

PPI use of ≥2-years was not associated with the risks of gastric (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 0.81-1.42), colorectal (OR: 1.05, 95% CI: 0.99-1.12), liver (OR: 1.14, 95% CI: 0.91-1.43), or pancreatic cancers (OR: 1.22, 95% CI: 0.89-1.67), compared to non-users. In exploratory analyses, elevated cancer risks were primarily restricted to those with ≥10 years of PPI use, but no consistent associations were found for increasing PPI dose and/or duration of use.

DISCUSSION

PPI use of ≥2 years was not associated with increased risks of gastrointestinal cancers. The cancer risks associated with PPI use of ≥10 years requires further study.

Long-term proton pump inhibitor usage and the association with pancreatic cancer in Sweden

BACKGROUND

The long-term safety of proton pump inhibitors (PPIs) is increasingly questioned. The aim of our study was to assess the risk of pancreatic cancer among long-term PPI users in Sweden.

METHODS

This population-based nationwide Swedish cohort study including 796,492 adult long-term PPI users has been used to calculate the standardized incidence rate ratios (SIRs) and 95% confidence intervals (CI) for pancreatic cancer, stratifying by indications of use, age, sex, and duration of use. The risk among all 20,210 long-term H2-receptor antagonist users was assessed as comparison.

RESULTS

Pancreatic cancer was found in 1733 long-term PPI users, and 25 H2-receptor antagonist users. For PPI users, the risk of pancreatic cancer was increased overall (SIRs = 2.22; 95% CI 2.12-2.32) and in all subgroup analyses, with the highest risk among PPI-users younger than 40 years (SIR = 8.90, 95% CI 4.26-16.37), and among individuals with a history of Helicobacter pylori (SIR = 2.99, 95% CI 2.54-3.49). After the first year after enrolment (during which PPI use may be because of early symptoms of pancreatic cancer), the risk remained increased over time, with SIR = 1.57 (95% CI 1.38-1.76) after 5 years. No associations were found for H2-receptor antagonists (SIR = 1.02, 95% CI 0.66-1.51).

CONCLUSIONS

This large study showed an increased risk of pancreatic cancer in long-term users of PPIs in Sweden, in particular among the youngest users.

Comparison of dysplastic fundic gland polyps in patients with and without familial adenomatous polyposis

AIMS

Dysplastic fundic gland polyps (d-FGPs) typically arise in patients with familial adenomatous polyposis (FAP) but may occur in non-syndromic patients. They rarely become malignant, but their significance is unclear, especially in non-syndromic patients. We aimed to compare d-FGPs in patients with and without FAP, using clinicopathologic findings and β-catenin immunohistochemistry (IHC).

METHODS AND RESULTS

We identified 124 fundic gland polyps with low-grade dysplasia (LGD) or high-grade dysplasia (HGD) or indefinite for dysplasia (IFD) from 66 patients (27 with FAP; 39 non-syndromic). We recorded patient sex, age at first d-FGP, time until subsequent d-FGP (if any), history of non-gastric cancer (no patients had gastric cancer), proton-pump inhibitor use, and the presence of Helicobacter pylori. β-Catenin IHC was performed on cases with available blocks. The mean age at d-FGP diagnosis was 31 years for FAP patients and 61 years for non-syndromic patients (P < 0.0001). Sixteen FAP patients (59%) developed at least one subsequent d-FGP, as compared with 10 (27%) non-syndromic patients (P = 0.0099). The median time between d-FGP detection was 11.5 months in FAP patients and 7 months in non-syndromic patients (P = 0.82). Six FAP patients (22%) and 17 non-syndromic patients (44%) had non-gastric malignancies (P = 0.11). β-Catenin IHC showed nuclear positivity in 14 of 112 (13%) d-FGPs: 12 of 94 with LGD, two of three with HGD, and none of 15 with IFD polyps.

CONCLUSIONS

Familial adenomatous polyposis patients develop d-FGPs earlier and more often develop additional ones than non-syndromic patients. d-FGPs in FAP and non-syndromic patients have similar low rates of β-catenin nuclear IHC positivity. FAP and non-syndromic patients developed non-gastric cancers at similar rates, suggesting that d-FGPs may portend a general increased risk of carcinogenesis in non-syndromic patients.