title: Eradication rate of Helicobacter pylori in a Mexican population at high risk for gastric cancer and use of serology to assess cure.
abstract: OBJECTIVE
  Helicobacter pylori causes gastric adenocarcinoma. We assessed the success of H. pylori eradication therapy in a medically underserved population in Chiapas, Mexico, that is at high risk for gastric cancer risk.
  
  
  METHODS
  Healthy volunteers with both antibodies to CagA and gastrin levels > or = 25 ng/ml were randomly assigned to receive either a combination of omeprazole, amoxicillin, and clarithromycin or matched placebo for 1 wk. Endoscopy with seven biopsies was performed at baseline, at 6 wk, and 1 yr after treatment. Treatment success was defined as loss of H. pylori by histological analysis. Cure was assessed using change in serology based on the standardized absorbance of a H. pylori ELISA.
  
  
  RESULTS
  H. pylori eradication rates were high (intent-to-treat analysis: 76.3% [95% CI = 68.7-84.0%] after 6 wk and 76.1% [95% CI = 67.7-84.6%] after 1 yr; per protocol analysis: 77.8% [95% CI = 70.1-85.4%] after 6 wk and 75.2% [95% CI = 66.5-84.0%] after 1 yr). Nine subjects on active treatment and one subject on placebo who were without H. pylori at 6 wk were infected at 1 yr (recurrence rates 10.7% and 33.3%, respectively, p = 0.31). Median changes in standardized absorbance at 1 yr were 47% and 1% for successfully and unsuccessfully treated patients, respectively. A 10% decline in standardized absorbance after 1 yr had 84% sensitivity and 100% specificity for H. pylori eradication.
  
  
  CONCLUSIONS
  Even with a short course of treatment against H. pylori, a high rate of eradication rate can be achieved in populations at high risk for stomach cancer. Serum antibodies are useful in assessing efficacy of therapy.
authors.affiliation: Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Mohar
authors.forename: Catherine
authors.initials: C
authors.lastname: Ley
authors.forename: Jeannette
authors.initials: J
authors.lastname: Guarner
authors.forename: Roberto
authors.initials: R
authors.lastname: Herrera-Goepfert
authors.forename: Luz-Sánchez
authors.initials: LS
authors.lastname: Figueroa
authors.forename: David
authors.initials: D
authors.lastname: Halperin
authors.forename: Julie
authors.initials: J
authors.lastname: Parsonnet
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology*; D000328:Adult; D000658:Amoxicillin / Q000008:administration & dosage; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D000897:Anti-Ulcer Agents / Q000008:administration & dosage; D000907:Antibodies, Bacterial / Q000032:analysis; D000942:Antigens, Bacterial / Q000032:analysis; D001426:Bacterial Proteins / Q000276:immunology / Q000378:metabolism; D017291:Clarithromycin / Q000008:administration & dosage; D004359:Drug Therapy, Combination; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005755:Gastrins / Q000097:blood; D005757:Gastritis, Atrophic / Q000188:drug therapy / Q000382:microbiology; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage; D010406:Penicillins / Q000008:administration & dosage; D011230:Precancerous Conditions / Q000188:drug therapy; D012372:ROC Curve; D012008:Recurrence; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology*
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D005755:Gastrins; D007074:Immunoglobulin G; D010406:Penicillins; C080866:cagA protein, Helicobacter pylori; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole