Primary gastric lymphoma: distribution and clinical relevance of different epidemiological factors

Institute of Hematology, University of Ferrara, Italy.

BACKGROUND. Over the last 10 years the incidence of primary gastric lymphomas (PGL), and in particular those of MALT origin, has significantly increased. Recent works correlated this epidemiological observation to Helicobacter pylori (HP) infection. On the other hand, new evidence demonstrating that occupational exposure to pesticides and solvents has played an important role in the pathogenesis of non-Hodgkin lymphomas (NHL) has emerged from studies involving large series of patients. METHODS. Thirty PGL patients, observed between 1986-1992, were subdivided according to HP infection, history of previous gastric disturbances (G) and exposure to pesticides and solvents (T). RESULTS. On the basis of these parameters we divided the patients into three groups: T+HP+ (8), T+HP- (7), T-HP+ (9). T+ patients had a positive history of gastric problems or a positive histological biopsy in 13.3% of cases, versus 66.7% in T- patients. The incidence of HP infection in the T+ group was 53%, which proved to be comparable to the statistics for northeastern Italy, while in the T- group the incidence of infection was 100%. CONCLUSIONS. On the whole these data suggest that HP infection could be considered a pathogenetic factor in 34% of patients, while occupational exposure to pesticides and solvents could have played a more important role in 66% of these cases.