An Article published Online First by The Lancet shows that the old style triple oral antibiotic therapy regimen to treat Helicobacter pylori infection works better than newer regimens in Latin America. This finding is the opposite of similar studies in Europe and parts of Asia, in which the newer four-pronged oral regimens are more effective. The authors, including Dr E Robert Greenberg, Cancer Research and Biostatistics, Seattle, WA, USA, and Dr William D Chey, University of Michigan, USA, and colleagues across the Americas, say that these findings justify starting population-wide H. pylori elimination trials across Latin America in order to prevent gastric cancers caused by this infection; but the authors of a linked Comment disagree.
The researchers did a randomised trial of empiric 14-day triple, 5-day concomitant, and 10-day sequential therapies for H. pylori in seven Latin American sites: Chile, Colombia, Costa Rica, Honduras, Nicaragua, and Mexico (two sites). Participants aged 21-65 years who tested positive for H. pylori by a urea breath test were randomly assigned to: 14 days of lansoprazole, amoxicillin, and clarithromycin (standard triple therapy, 488 patients); 5 days of lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant therapy, 489 patients); or 5 days of lansoprazole and amoxicillin followed by 5 days of lansoprazole, clarithromycin, and metronidazole (sequential therapy, 486 patients). Eradication was assessed by a further urea breath test 6-8 weeks after randomisation.
Eradication rates were highest with standard therapy at 82%, compared with 74% for concomitant therapy and 77% with sequential therapy. Neither four-drug regimen was significantly better than standard triple therapy in any of the seven sites. The authors say: "Our findings showed that in the Latin American populations we studied, by contrast with those for European and some Asian populations, 14-day standard triple therapy is more effective than 5-day concomitant or 10-day sequential four-drug regimens that include metronidazole for eradication of H. pylori . Thus, effectiveness of H. pylori eradication regimens in one area might not be as equally effective elsewhere."
The authors add that the study was designed, as a preliminary step towards implementation of programmes of gastric cancer prevention in Latin America, since they note "analyses have suggested that H. pylori eradication programmes would be cost effective over the long term if they prevented only 10% of gastric cancer deaths; over the short term they would reduce costs of care for peptic ulcers and dyspepsia symptoms. Eradication programmes are potentially even more cost effective in regions such as Latin America, where the burden of H. pylori -associated diseases is high."
They conclude: "Our results suggest that population-wide clinical trials or public health programmes of H. pylori eradication are feasible in Latin America."
However, in a linked Comment, Dr Luiz Edmundo Mazzoleni, Dr Carlos Fernando Francesconi and Dr Guilherme Becker Sander, Universidade Federal do Rio Grande do Sul and Hospital de Clínicas de Porto Alegre, Brazil, say: "A disturbing issue presented by Greenberg and colleagues is the suggestion of developing a mass eradication programme for H. pylori in Latin America, aimed at long-term prevention of at least 10% of gastric cancer cases... Although the role of H. pylori in gastric carcinogenesis is well-defined, no definitive evidence shows that mass eradication could reduce incidence of gastric cancer."
They say: "Policies aimed at population-wide H. pylori eradication could have individual and the social repercussions. Amoxicillin could cause fatal anaphylactic reactions, while clarithromycin has been associated with increased mortality in patients with ischaemic heart disease. Furthermore almost all antibiotics can cause Clostridium difficile infection, which could eventually become life threatening. Even if infrequent, these complications could become important when eradicating H. pylori at a population level."
They conclude: "Mass eradication is a major issue requiring further investigation... [it] is potentially feasible but in view of the differing socioeconomic realities of Latin American countries, doubts remain about the advisability of such a policy."
Dr E Robert Greenberg,Cancer Research and Biostatistics, Seattle, WA, USA. T) +1-206-780-9942 E) e.r.greenberg@dartmouth.edu
Dr William D Chey, University of Michigan, USA. T) +1 734-936-4775 E) wchey@umich.edu
For Spanish or English speaking media: Dr Douglas Morgan, University of North Carolina, Chapel Hill, NC, USA. T) +1 919-966-0764 E) douglas_morgan@med.unc.edu
For Spanish speaking media: Dr Javier Torres, Instituto Mexicano del Seguro Social, Mexico City, Mexico. T) +52-55-56276940 E) jtorresl57@yahoo.com.mx
Dr Luiz Edmundo Mazzoleni and Dr Carlos Fernando Francesconi Universidade Federal do Rio Grande do Sul and Hospital de Clínicas de Porto Alegre, Brazil. Contact via e-mail. E) lemazzoleni@yahoo.com.br
The Lancet