Primary gastrointestinal non-Hodgkin's lymphoma. A population based study in central Finland in 1975-1993.

Gastrointestinal lymphomas have been uncommon, but the frequency of their predisposing conditions is increasing. The objective of the present study is to determine the frequency of gastrointestinal lymphomas in the area of central Finland as well as the influence of clinical features and therapeutical approaches on the survival of these patients. All samples of gastrointestinal non-Hodgkin's lymphomas diagnosed of patients living in the province of central Finland in 1975-1993 were re-examined. In central Finland the mean annual frequency of new gastrointestinal lymphomas was 10/1000000 in 1975-1984 and 16.0/1000000 in 1985-1993. The total incidence of gastrointestinal lymphomas in Finland adjusted for age to the world standard population was 12.5/1000000 in 1992. Two patients with peripheric T-cell lymphoma had a coeliac disease. Other predisposing conditions were not found. The stage of distribution of the lymphoma (p < 0.01) and radicality of the surgery (p < 0.01) were the most influencing factors on the survival of these patients. In conclusion the early distinction of gastrointestinal lymphomas is vital because of an increasing frequency of predisposing factors and a better prognosis due to new combination therapies.