Incidence and survival of gastric non-Hodgkin's lymphoma: a population-based study from the Association of the French Cancer Registries (FRANCIM).

BACKGROUND: Most epidemiological studies on gastric lymphomas (GL) were carried out before changes in therapy were introduced. The aim of the study was to measure the incidence of GL and to estimate survival. MATERIAL AND METHODS: Data were provided by the Association of the French Cancer Registries database. Age-standardized incidence rates were calculated for 786 incident cases diagnosed between 1978 and 2002. Crude and relative survival were calculated for 361 cases diagnosed between 1989 and 1997. Effects specific to sex, age at diagnosis, year of diagnosis, and grade of malignancy were estimated in multivariate analysis. RESULTS: Incidence was stable during the study period. However, high-grade GL frequency increased whereas low-grade and not otherwise specified (NOS) GL frequencies were respectively stable and decreased. At 5 years, relative survival was 63% in men and 60% in women. Patients aged 75 or older had a five-year relative survival of 33%. Age at diagnosis was the only significant prognostic factor in multivariate analysis. Time trend improvement in prognosis was observed. DISCUSSION: Results in elderly patients show that therapeutic regimens should be specifically designed and assessed for them. The prognosis improvement trend is probably related to the implementation of changes in management of patients and has to be confirmed by more recent data