Helicobacter pylori eradication failure may have confounded the recent large-scale health database study that showed proton pump inhibitors increase gastric cancer risk

Proton Pump Inhibitors and Gastric Cancer

Concerns have been raised regarding the long-term use of proton pump inhibitors (PPIs) as an important risk factor for gastric cancer in clinical practice. PPIs can cause hypergastrinemia at clinical doses, and hypergastrinemia has been reported to induce malignant neoplasms in the stomach in previous animal studies. In humans, the proliferation of enterochromaffin-like (ECL) cells induced by hypergastrinemia is suspected as a potential mechanism of gastric cancer. Meanwhile, persistent Helicobacter pylori (H. pylori) infection causes gastric atrophic change, which itself is a major cause of gastric cancer, and it can further increase the risk of gastric cancer by strengthening corpus atrophy through interaction with PPIs. Recent epidemiologic studies have reported an important link between long-term PPI intake and gastric cancer risk even after successful eradication of H. pylori. However, due to the methodological limitations of observational clinical studies, the causal relationship is still not clear, and a recent big data-based study reported that long-term PPI use was not related to gastric cancer incidence. Taken together, despite the potential detrimental effects of PPIs, it is currently difficult to draw a definite conclusion about its association with gastric cancer. To minimize the possibility of gastric cancer in H. pylori-infected patients or precancerous lesions in long-term PPI users, long-term PPI administration should be limited to the minimum effective dose, and antibacterial treatment for H. pylori should be considered.

Cost-effectiveness analysis of two routine therapeutic methods for Helicobacter pylori eradication: a Persian cohort-based study

AIM

This study aimed to analyze the cost-effectiveness of two routine therapeutic methods for H. pylori eradication in Iran.

BACKGROUND

Because of the importance of Helicobacter pylori (H. pylori) eradication on gastric cancer prevalence and costs, an economic analysis of the eradication methods is essential for health systems.

METHODS

This cross-sectional study was conducted on 7,496 participants with positive Hepadnaviridae (HPsAg) test results for H. pylori; 6,163 of them were treated with furazolidone (group A), and 1,333 participants were treated with clarithromycin (group B). Data on GP visits, medications, and HPsAg costs as direct costs and absence from work and transportation as indirect costs was collected by researcher-made questionnaire. Indirect costs were calculated based on face-to-face interviews with 365 patients of the Persian Cohort Center. Successful eradication of H. pylori infection (negative HPsAg) was defined as the effectiveness of the interventions. Incremental cost-effectiveness ratio (ICER) was used to compare the overall results.

RESULTS

The total direct cost of H. pylori for groups A and B were estimated at 13.7 and 5.83 billion IRR, respectively. The highest and lowest percentages of total costs were the cost of diagnostic services and the time cost, respectively. There was a significant difference between the two groups in drug costs (p<0.001). The effect ratio for groups A and B was 85.93% and 96.54%, respectively. Cost per effectiveness was higher for clarithromycin (CE=3,250,170 IRR) than for furazolidone (CE=2,988,488 IRR), and ICER showed that 5.1 Million IRR per participant is needed to eradicate H. pylori.

CONCLUSION

Based on the results, furazolidone was more cost-effective than clarithromycin for H. pylori treatment. Therefore, due to the high prevalence of H. pylori and the economic conditions of the health system in Iran, furazolidone can be a cost-effective choice between the two conventional treatment methods considering the results of further research and possible side effects.

Review: Gastric cancer-Clinical aspects

Gastric cancer (GC) was responsible for over 1 000 000 new cases in 2018 and an estimated 783 000 deaths, making it still the fifth most frequently diagnosed cancer and the third leading cause of cancer deaths in both sexes worldwide. Divergent trends for GC incidence were observed in the USA. Incidence rates, particularly for non-cardia GC, were stable or increasing among persons aged <50 years. In an analysis of data from a public hospital database in Hong Kong, treatment of Helicobacter pylori infection was associated with a lower risk of GC, particularly in older subjects who received treatment ≥10 years before. Based on the results of a 16-year endoscopy-based follow-up eradication trial, patients with incomplete-type intestinal metaplasia (IM) should receive endoscopic surveillance upon H. pylori eradication therapy. Updated guidelines on the endoscopic surveillance of preneoplastic conditions of the stomach (MAPS II) have been published. In the RAINFALL trial, the addition of ramucirumab to a backbone chemotherapy as a first-line regimen failed to improve overall survival (OS) of patients with metastatic disease. Also, pembrolizumab did not prolong OS when compared to paclitaxel in the second-line treatment of patients with advanced GC or esophagogastric junction (EGJ) cancer. Trifluridine/tipiracil improved OS by 2.1 months in the third or further treatment line of patients with advanced GC. In a systematic investigation conducted on Chinese patients with GC, CLDN18-ARHGAP26/6 fusion was associated with signet-ring cell content and was prognostic for a worse outcome and predictive for no benefit from oxaliplatin/fluoropyrimidine-based chemotherapy. Organoid cultures represent an appealing model that may be applied for therapy response testing in the near future.

Rifabutin and Furazolidone Could Be the Candidates of the Rescue Regimen for Antibiotic-Resistant H. pylori in Korea

Background/Aim. In Korea, the rate of Helicobacter pylori (H. pylori) eradication has declined steadily as a result of increasing resistance to antibiotics, especially dual resistance to clarithromycin and metronidazole. However, microbiological culture data on drug-resistant H. pylori is lacking. This study evaluated the antimicrobial efficacy of candidate antibiotics against resistant H. pylori strains. Methods. After retrospectively reviewing the data from the Helicobacter Registry in Gil Medical Center (GMC) and Asan Medical Center (AMC), along with 4 reference strains, we selected the 31 single- or multidrug-resistant strains. The susceptibility of the H. pylori strains to seven antibiotics (clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, rifabutin, and furazolidone) and minimum inhibitory concentration were tested using the broth microdilution technique. Results. Among 31 antibiotic resistance strains for H. pylori, there were no strains resistant to rifabutin or furazolidone, which had MICs of <0.008 and 0.5 μg/mL, respectively. Only one tetracycline-resistant strain was found (MIC < 2 μg/mL). Amoxicillin and levofloxacin were relatively less effective against the H. pylori strains compared to rifabutin or furazolidone (resistance rates 22.6%, 1.9%, respectively). Tetracycline showed the relatively low resistance rates (3.2%) for H. pylori strains. Conclusions. Therefore, along with tetracycline which has already been used as a component for second-line eradication regimen for Helicobacter, rifabutin and furazolidone, alone or in combination, could be used to eradicate antibiotic-resistant H. pylori strains where drug-resistant Helicobacter spp. are increasing.

Estimates of all cause mortality and cause specific mortality associated with proton pump inhibitors among US veterans: cohort study

OBJECTIVE

To estimate all cause mortality and cause specific mortality among patients taking proton pump inhibitors (PPIs).

DESIGN

Longitudinal observational cohort study.

SETTING

US Department of Veterans Affairs.

PARTICIPANTS

New users of PPIs (n=157 625) or H2 blockers (n=56 842).

MAIN OUTCOME MEASURES

All cause mortality and cause specific mortality associated with taking PPIs (values reported as number of attributable deaths per 1000 patients taking PPIs).

RESULTS

There were 45.20 excess deaths (95% confidence interval 28.20 to 61.40) per 1000 patients taking PPIs. Circulatory system diseases (number of attributable deaths per 1000 patients taking PPIs 17.47, 95% confidence interval 5.47 to 28.80), neoplasms (12.94, 1.24 to 24.28), infectious and parasitic diseases (4.20, 1.57 to 7.02), and genitourinary system diseases (6.25, 3.22 to 9.24) were associated with taking PPIs. There was a graded relation between cumulative duration of PPI exposure and the risk of all cause mortality and death due to circulatory system diseases, neoplasms, and genitourinary system diseases. Analyses of subcauses of death suggested that taking PPIs was associated with an excess mortality due to cardiovascular disease (15.48, 5.02 to 25.19) and chronic kidney disease (4.19, 1.56 to 6.58). Among patients without documented indication for acid suppression drugs (n=116 377), taking PPIs was associated with an excess mortality due to cardiovascular disease (22.91, 11.89 to 33.57), chronic kidney disease (4.74, 1.53 to 8.05), and upper gastrointestinal cancer (3.12, 0.91 to 5.44). Formal interaction analyses suggested that the risk of death due to these subcauses was not modified by a history of cardiovascular disease, chronic kidney disease, or upper gastrointestinal cancer. Taking PPIs was not associated with an excess burden of transportation related mortality and death due to peptic ulcer disease (as negative outcome controls).

CONCLUSIONS

Taking PPIs is associated with a small excess of cause specific mortality including death due to cardiovascular disease, chronic kidney disease, and upper gastrointestinal cancer. The burden was also observed in patients without an indication for PPI use. Heightened vigilance in the use of PPI may be warranted.

Proton pump inhibitor: The dual role in gastric cancer

Proton pump inhibitors (PPIs) are one of the most frequently used medications for upper gastrointestinal diseases. However, a number of physicians have raised concern about the serious side effects of long-term use of PPIs, including the development of gastric cancer. Recent epidemiological studies have reported a significant association between long-term PPI intake and the risk of gastric cancer, even after successful Helicobacter pylori eradication. However, the effects of PPIs on the development of pre-malignant conditions such as atrophic gastritis or intestinal metaplasia are not fully known, suggesting the need for comprehensive and confirmative studies are needed in the future. Meanwhile, several experimental studies have demonstrated the effects of PPIs in reducing chemoresistance in gastric cancer cells by modulating the acidic microenvironment, cancer stemness and signal transducer and activator of transcription 3 (STAT3) signaling pathway. The inhibitory effects of PPIs on STAT3 activity may overcome drug resistance and enhance the efficacy of conventional or targeted chemotherapeutic agents. Taken together, PPIs may “play dual role” in gastric carcinogenesis and treatment of gastric cancer.

Gastric cancer: epidemiology, prevention, and therapy

Gastric cancer (GC) is still the third leading cause of cancer death in both sexes worldwide. Helicobacter pylori infection is the most important risk factor for GC and, in spite of the consistent trend of a decreasing incidence, in 2015 approximately 4.4 billion individuals-more than half the world's population-were infected with H. pylori. The birth cohort pattern of decreased H. pylori infection reported in a systematic review contributes to explain the declining GC mortality in Japan. Current trends in estimated annual percentage change of GC incidence foreshadow expected reversals in both falling incidence and male predominance among US non-Hispanic whites. Combining serum pepsinogen 1 and H. pylori serology was shown to be useful for GC risk stratification in a Finnish population. Gastritis staging by operative link on gastritis assessment was confirmed to be reliable in predicting GC risk in a large prospective study. In a randomized trial from South Korea, H. pylori eradication therapy significantly reduced the rates of metachronous GC in patients who received curative endoscopic resection for early GC. A study based on a territory-wide health care database of the Hong Kong Hospital Authority showed that aspirin use is associated with a reduced GC risk. Another study based on the same database showed that proton pump inhibitors increase GC risk, but methodological biases have most likely acted as confounders. Confirmatory data on the role of endoscopic submucosal dissection in patients with early GC have been published. The phase III FLOT4 trial has shown that the FLOT triplet regimen (docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil) improves the outcome of patients with GC and locoregional disease as compared to the ECF triplet (epirubicin, cisplatin, and 5-fluorouracil). In the phase III ATTRACTION-2 trial, nivolumab was shown to be an effective treatment option with a relative safe profile for heavily pretreated patients with advanced GC.

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.