Trends in the eradication rates of Helicobacter pylori infection for eleven years

AIM:To evaluate the trends in the eradication rate of Helicobacter pylori(H.pylori) over the past 11 years in a single center.METHODS:This retrospective study covered the period from January 2000 to December 2010.We evaluated 5746 patients diagnosed with gastric ulcers(GU),duodenal ulcers(DU),GU + DU,or nonpeptic ulcers associated with an H.pylori infection.We treated them annually with the 2 wk standard first-line triple regimen,proton pump inhibitor(PPI) + amoxicilin + clarithromycin(PAC;PPI,clarithromycin 500 mg,and amoxicillin 1 g,all twice a day).The follow-up test was performed at least 4 wk after the completion of the 2 wk standard H.pylori eradication using the PAC regimen.We also assessed the eradication rates of 1 wk second-line therapy with a quadruple standard regimen(PPI b.i.d.,tripotassium dicitrate bismuthate 300 mg q.i.d.,metronidazole 500 mg t.i.d.,and tetracycline 500 mg q.i.d.) after the failure of the first-line therapy.Statistical analysis was performed with 95%CI for the differences in the annual eradication rates.RESULTS:A total of 5746 patients [2333 males(58.8%),1636 females(41.2%);mean age of males vs females 51.31 ± 13.1 years vs 52.76 ± 13.6 years,P < 0.05,total mean age 51.9 ± 13.3 years(mean ± SD)] were investigated.Among these patients,1674 patients were excluded:35 patients refused treatment;18 patients ceased H.pylori eradication due to side effects;1211 patients had inappropriate indications for H.pylori eradication,having undergone stomach cancer operation or chemotherapy;and 410 patients did not undergo the follow-up.We also excluded 103 patients who wanted to stop eradication treatment after only 1 wk due to poor compliance or the side effects mentioned above.Finally,we evaluated the annual eradication success rates in a total of 3969 patients who received 2 wk first-line PAC therapy.The endoscopic and clinical findings in patients who received the 2 wk PAC were as follows:gastric ulcer in 855(21.5%);duodenal ulcer in 878(22.1%);gastric and duodenal ulcer in 124(3.1%),erosive,atrophic gastritis and functional dyspepsia in 2055(51.8%);and other findings(e.g.,MALToma,patients who wanted to receive the therapy even though they had no abnormal endoscopic finding) in 57(0.5%).The overall eradication rate of the 2 wk standard firstline triple regimen was 86.5%.The annual eradication rates from 2000 to 2010 were 86.7%,85.4%,86.5%,83.3%,89.9%,90.5%,88.4%,84.5%,89.1%,85.8%,and 88.3%,sequentially(P = 0.06).No definite evidence of a significant change in the eradication rate was seen during the past eleven years.The eradication rates of second-line therapy were 88.9%,82.4%,85%,83.9%,77.3%,85.7%,84.4%,87.3%,83.3%,88.9%,and 84%(P = 0.77).The overall eradication rate of 1 wk quadruple second-line therapy was 84.7%.There was no significant difference in the eradication rate according to the H.pylori associated diseases.CONCLUSION:This study showed that there was no trend change in the H.pylori eradication rate over the most recent 11 years in our institution.

Analysis of microsatellite instability in stool DNA of patients with colorectal cancer using denaturing high performance liquid chromatography

AIM: To evaluate the usefulness of denaturing high performance liquid chromatography (DHPLC) for analyzing microsatellite instability (MSI) status in stool DNA of patients with colorectal cancer. METHODS: A total of 80 cancer tissues from patients with primary sporadic colorectal tumor (proximal cancer: 27, distal cancer: 53) and matched stool (which were employed for comparison with the tissues) were analyzed for MSI status in BAT 26. DNA samples extracted from stool were evaluated by nested polymerase chain reaction (PCR) and DHPLC for MSI analysis. RESULTS: Six cases (7.5%) of MSI were identified in BAT 26 from 80 cancer tissues. All the stool DNA samples from patients whose cancer tissue showed MSI also displayed MSI in BAT 26. CONCLUSION: As MSI is one of the established fecal DNA markers to screen colorectal cancer, we propose to use DHPLC for the MSI analysis in fecal DNA.