H. pylori and gastric cancer: limitations of retrospective studies

Funduscopic results after 4-year follow-up treatment with ranibizumab for age-related macular degeneration in a region of Spain

Background

The study aims to survey longstanding funduscopic and functional outcomes of age-related macular degeneration (AMD) after ranibizumab treatment and verify the accuracy of a new method to compare the retinal thickness measured with different optical coherence tomography (OCT) tools.

Methods

Case series included 314 eyes with 2–4 years of follow-up. Main Outcome Measures were visual acuity (VA), number of injections, retinal thickness, OCT morphology, and final macular funduscopic status.

Results

One hundred twenty-two men and 177 women (mean age, 78.3 years) were included. The mean time to the first injection was 17.3 ± 14.6 days. Initial VA was O.8(20/125) ± 0.5; 0.7(20/100) ± 0.5 at 3 months; 0.8(20/125) ± 0.5 at a year; 1(20/200) ± 0.6 at year 2; 1(20/200) ± 0.6 at year 3 and 1.1(20/250) ± 0.6 at year 4. Number of visits at 3 months was 2.7 ± 0.8; 7.3 ± 2.1 at a year; 5.2 ± 2.7 along the 2nd year; 3.9 ± 2.3 at year 3 and 3.6 ± 2.2 at year 4. Number of injections at 3 months was 2.6 ± 0.5; 3.9 ± 1.5 at a year; 1.1 ± 1.5 along the 2nd year; 1.5 ± 2.4 at year 3 and 1.8 ± 3.1 at year 4. Patients with worse VA outcomes received more injections and were older. The formula to calculate changes in retinal thickness showed a 30% reduction in thickness, which correlated well with the OCT morphology. Patients with polypoidal choroidal vasculopathy (PCV) had a worse final outcome. The final disciform macular status (37%) was related to fewer injections and a greater decrease in thickness. Final well-preserved maculas (12.%) needed more injections and treatment changes; those that were atrophic at the final visit (30.8%) had a worse initial VA and greater decrease in thickness at the 3-month visit.

Conclusions

Younger patients had better final outcomes. Our method to compare retinal thickness using different OCT tools worked well. The final visual outcome after a long follow-up was poor, which may be related to advanced age, poor initial VA, and the high incidence of final fibrosis or atrophy.

Relapse prevention in reflux oesophagitis with regard to Helicobacter pylori status: a double-blind, randomized, multicentre trial to compare the efficacy of pantoprazole versus ranitidine

OBJECTIVE

To compare prospectively the effectiveness of 1 year's treatment with pantoprazole versus ranitidine in order to prevent relapse after initial cure of reflux oesophagitis. For the first time the influence of the initial Helicobacter pylori status on therapeutic results was also taken into account.

METHODS

In order to cure reflux oesophagitis, 396 patients with Savary/Miller stage II or III reflux oesophagitis were treated with pantoprazole 40 mg once daily for 8 weeks. Those who were H. pylori positive (n = 140) were also given 1 week of eradication treatment with clarithromycin 2 x 250 mg daily, metronidazole 2 x 400 mg daily, and a further 40 mg pantoprazole daily. The 303 patients who were endoscopically cured after the 8-week period were randomized and treated with either pantoprazole 20 mg (n = 199) or ranitidine 150 mg (n = 104) daily in double-blind fashion. The primary objective was to assess the time to endoscopically proven recurrence of reflux oesophagitis.

RESULTS

In the intention-to-treat (ITT) population, 66.3% (118/178) of the pantoprazole group and 34.0% (32/94) of the ranitidine group showed neither endoscopic nor clinical symptoms of relapse after the 1-year treatment period (P < 0.0001) (per-protocol populations: 70.3% [109/155] in the pantoprazole group and 39.4% [28/71] in the ranitidine group). In the pantoprazole group, the relapse rate in initially H. pylori-positive patients who underwent eradication was 30.9% (17/55) and in H. pylori-negative patients 29% (29/100).

CONCLUSIONS

Long-term treatment with 20 mg pantoprazole daily to prevent relapse of reflux oesophagitis in H. pylori-negative patients is significantly more effective than 150 mg ranitidine daily. The initial H. pylori eradication treatment does not influence the outcome of the long-term treatment.

Screening for gastric cancer by Helicobacter pylori serology: a retrospective study

BACKGROUND

Screening by serology for Helicobacter pylori in young dyspeptic patients has been shown to be effective in reducing demand for endoscopy. H. pylori has been implicated in the causation of gastric cancer and the reported seropositivity rate in patients with gastric cancer ranges from 69 to 94 per cent. The aim of this study was to assess the potential value of Helicobacter antibodies as a method of selecting dyspeptic patients over the age of 45 years for endoscopy.

METHODS

A retrospective comparison of the antibody status to H. pylori was made between 154 patients with gastric cancer and a sex- and date of birth-matched dyspeptic control group. Results from the former group were correlated with demographic data and tumour characteristics.

RESULTS

Significantly more patients with gastric cancer were seropositive than controls (77 versus 66 per cent). H. pylori was not related to the Laurén classification of the tumour. Tumour site was significant: body and antrum tumours were associated with Helicobacter whereas cardial tumours appeared to be unrelated.

CONCLUSION

Screening by antibody assays to H. pylori would miss more than 30 per cent of current gastric cancers. The increasing incidence of cardial cancer would cause this percentage to rise in the future.

Eradication of Helicobacter pylori infection in patients with non-ulcer dyspepsia. Effects on basal and bombesin-stimulated serum gastrin and gastric acid secretion

BACKGROUND

This study evaluates the effect of eradicating Helicobacter pylori on basal and bombesin-stimulated gastric acid secretion and serum gastrin in non-ulcer dyspepsia.

METHODS

Before and 1 month after an attempt to eradicate H. pylori basal and bombesin-stimulated gastric acid outputs were measured in 23 patients. H. pylori was eradicated in 15 patients (group A) but not in the other 8 (group B). Incremental gastric acid output was calculated by subtracting basal from bombesin-stimulated values.

RESULTS

Basal acid output increased significantly (p = 0.01) after therapy in group A (delta 1.6 +/- 0.6 mmol/h) but not in group B (delta 0.2 +/- 0.5 mmol/h). Incremental gastric acid output decreased distinctly (delta-3.9 +/- 1.4 mmol/h) after therapy in group A (p = 0.02) but not in group B (delta-2.2 +/- 1.7 mmol/h). Basal serum gastrin decreased significantly (p < 0.005) after therapy in group A (delta-9 +/- 4 pM) but not in group B (delta-1 +/- 2 pM). Integrated serum gastrin responses to bombesin decreased markedly (p < 0.001) after therapy in group A (delta-5.0 +/- 1.6 nM*60 min) but slightly in group B (delta-0.9 +/- 1.3 nM*60 min) (p < 0.05).

CONCLUSIONS

In patients with non-ulcer dyspepsia basal serum gastrin concentrations decrease but basal gastric acid outputs increase after eradication of H. pylori. Bombesin-induced increments in gastric acid output, however, decrease in parallel with gastrin release.

Bacteria in the aetio-pathogenesis of gastric cancer: a review

Severe atrophic gastritis, a precursor lesion of gastric carcinoma, is connected, in two different ways, with intragastric bacterial colonization: (1) in advanced atrophic body gastritis (type A), achlorhydria or severe hypochlorhydria leads to bacterial overgrowth with aerobic and anaerobic flora enabling the conversion of nitrate to nitrite and further to N-nitroso compounds; (2) the newly re-discovered Helicobacter pylori is probably one of the major causes of chronic atrophic antral gastritis (type B). Both types of bacteria may be involved in the pathogenesis of multifocal gastritis (type AB). In the western world, achlorhydric atrophic gastritis is not only found in pernicious anaemia but is latent in about 2 to 6% of the general population. In one study from the Mayo Clinic, about one-third of consecutive gastric carcinomas were present in achlorhydric stomachs, the remainder in acid-secretors. Apart from the N-nitroso compounds, other carcinogenic mechanisms may be active in type A gastritis: elevated serum gastrin; altered cell turnover; immunologic and hereditary traits. The association of H. pylori with gastric carcinoma is mainly based on circumstantial evidence: (i) epidemiological studies indicate a moderately increased risk for gastric cancer in H. pylori-positive subjects compared with H. pylori-negative; (ii) in the presence of H. pylori intragastric levels of the anti-oxidant ascorbic acid are lowered; (iii) H. pylori seems to be linked to mucosal atrophy and intestinal metaplasia; (iv) recent follow-up studies show a significant development of atrophic gastritis in H. pylori-positive patients compared to H. pylori-negative.(ABSTRACT TRUNCATED AT 250 WORDS)