Helicobacter pylori, gastric cancer and other gastrointestinal malignancies.

In a retrospective study performed in California, U.S.A., ca. 3% of patients with gastric intestinal metaplasia (GIM) developed gastric cancer (GC) within a median time period of 4.6 years after diagnosis of GIM. This observation stresses the importance of targeted surveillance even in regions with a low GC prevalence. Patients with alcoholic liver disease as well as survivors of colorectal and lobular breast cancer were found to be at increased risk of secondary GC. A population-based Chinese study confirmed "serologic biopsy" as a useful screening tool for stratifying the individual risk of developing GC. Concerning GC therapy, a post hoc analysis of the MAGIC trial reported that regression of lymph node metastases, but not the tumor regression itself, predicts overall survival. Furthermore, in patients with high microsatellite instable tumors, perioperative chemotherapy leads to an increased risk of mortality. Two studies confirmed that eradication therapy is worthwhile as an initial treatment for gastric mucosa-associated lymphoid tissue (MALT) lymphoma irrespective of the H. pylori infection status and stage. An increased risk of a second primary malignancy including GC was observed in these patients treated with immuno/chemotherapy but not in patients treated solely with an H. pylori eradication treatment. With respect to gastrointestinal malignancies other than GC, discrepant data have been published regarding the association of H. pylori with pancreatic cancer whereas no association has been reported with esophageal squamous cell carcinoma. The majority of published studies still support an association of H. pylori with colon neoplasms.