Long-term proton pump inhibitor use and gastrointestinal cancer.
ABSTRACT Proton pump inhibitors profoundly affect the stomach and have been associated with carcinoid tumors in female rats. There is now sufficient experience with this class of drugs to allow reasonable estimation of their safety in terms of cancer development in humans. Long-term use of proton pump inhibitors is associated with an increase in gastric inflammation and development of atrophy among those with active Helicobacter pylori infections. The actual risk is unknown but is clearly low. However, it can be markedly reduced or eliminated by H. pylori eradication. It is thus recommended that patients being considered for long-term proton pump inhibitor therapy should be tested for H. pylori infection and, if present, this pathogen should be eradicated. Oxyntic cell hyperplasia, glandular dilatations, and fundic gland polyps may develop in patients not infected with H. pylori, but these changes are believed to be reversible and without significant cancer risk.
Article: Gastric mucosa during treatment with lansoprazole: Helicobacter pylori is a risk factor for argyrophil cell hyperplasia.[show abstract] [hide abstract]
ABSTRACT: The mechanisms causing progression of fundic gastritis and changes in argyrophil cell morphology in patients undergoing long-term treatment with proton pump inhibitors are unknown. The hypothesis of this study was that Helicobacter pylori is a risk factor for both gastritis and argyrophil cell hyperplasia. Forty-two patients with peptic disorders resistant to H2-blockers were treated with 30-90 mg lansoprazole daily for up to 5 years. Serum gastrin levels, antral gastrin cells, fundic argyrophil cells, parameters of gastritis, and H. pylori infection were evaluated regularly. In nonantrectomized patients, serum gastrin levels increased from a median of 76 pg/mL to 163 pg/mL within 3 months. Antral gastrin cell density increased from 175 to 267 cells/mm2 (P < 0.001), and fundic argyrophil cell density increased from 83 to 149 cells/mm2 (P < 0.001). Chronic inflammation, activity, and atrophy of the oxyntic mucosa worsened exclusively in patients with H. pylori infection. Linear and/or micronodular argyrophil cell hyperplasia was diagnosed in 2.6% of patients before lansoprazole and in 29.2% after 5 years treatment. These changes were significantly related to serum gastrin levels, H. pylori infection, chronic inflammation, and atrophy of the oxyntic mucosa. H. pylori represents an important factor for the progression of fundic gastritis and the development of argyrophil cell hyperplasia during long-term treatment with lansoprazole.Gastroenterology 03/1997; 112(3):707-17. · 11.68 Impact Factor
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ABSTRACT: Chronic acid suppression by proton pump inhibitor therapy can lead to hypergastrinemia. Because existing evidence suggested an association between hypergastrinemia and colorectal cancer, we examined whether long-term proton pump inhibitor use is associated with an increased risk of colorectal cancer in a population-representative cohort. We conducted a nested case-control study among patients 50 years of age and older and with > or =5 years of colorectal cancer-free initial follow-up in the General Practice Research Database (1987-2002) from the United Kingdom. Cases consisted of all patients with an incident diagnosis of colorectal cancer. Using incidence density sampling, up to 10 controls were matched with each case on practice site and both duration and calendar time of follow-up before the index date. The primary exposure of interest was > or =5 years of cumulative proton pump inhibitor therapy. We assessed the presence of duration-response and dose-response effects. We identified 4432 incident colorectal cancer cases and 44,292 controls. The adjusted odds ratio for > or =5 years of proton pump inhibitor exposure was 1.1 (95% confidence interval, 0.7-1.9). Among high-dose proton pump inhibitor users (ie, > or =1.5 defined daily doses/day), there was a nonstatistically significant trend toward an increased risk with increasing duration of use (test for trend, P = .2). However, patients with pernicious anemia were not at increased risk for colorectal cancer (adjusted odds ratio, 0.9; 95% confidence interval, 0.6-1.3). Long-term proton pump inhibitor therapy at a regular dose is not associated with a significantly increased risk of colorectal cancer.Gastroenterology 09/2007; 133(3):748-54. · 11.68 Impact Factor