Helicobacter pylori infection and gastric MALTomas: an up-to-date and therapy highlight

Abstract

During the last 20 years Helicobacter pylori (Hp) has been, undoubtly, the star of gastroenterology and microbiology, so much to deserve the "Nobel prize 2005" for biology and medicine to its discoverers. More recently, an increased interest arised on Hp and its linkages with other medical fi elds such as immunology, surgery and dentistry. The outcome of the pathologies due to such bacterium is dependent on many factors, including bacterial genotype, host physiology and genetics, and environmental factors such as diet. In spite of its clear involvement in some pathologies like acute and chronic gastritis, peptic ulcer and gastric cancer, very little is known about another pathology recently proved to be closely associated to the infection by Hp: the gastric MALToma, which account for 7% of all newly diagnosed non-Hodgkin's lymphoma. The chronic infection of the gastric mucosa from Helicobacter pylori primes a complex pathogenic process which could determine the onset of the gastric cancer through some intermediary steps. On these bases, in 1994, the International Agency for Cancer Research (IARC) defined this bacterium a "class I carcinogenic agent" for gastric cancer. The MALT lymphomas are the most frequent lymphoid neoplasms of the digestive tract; we can also observe other and more rare lymphomatous tumours with specific clinical patterns, like the T-lymphoma associated with lymphomatous polyposis and enteropathy. The development of gastric lymphomas is usually preceded by the acquisition of lymphatic tissue, after inflammatory stimuli and particularly after the infection from Hp, which organizes itself with the characteristics of the MALT. Recently, a number of papers have highlighted the remarkable efficacy of Hp eradicating therapy in patients with low-grade MALT lymphoma of the stomach without other modalities, e.g. surgery and systemic chemotherapy. The aim of this study is to be helpful for a comprehensive understanding the possible connections between Hp and gastric MALT lymphoma, evaluating the best therapy strategies, surgical and non surgical, actually available for its treatment.