Non-Hodgkin's lymphoma: time trends for incidence and survival in Côte-d'Or, France

Abstract

Background: A generally reported increased incidence of non-Hodgkin's lymphomas (NHL) and a recent evolution in treatment strategies, as well as several clinical trials suggesting improved survival, have prompted this study to evaluate time trends in incidence and prognosis of NHL.

Method: NHL recorded by the population-based Registry of Hematopoietic Malignancies in Côte-d'Or (France) were considered over three 4-year periods from 1980 to 1992. A multivariate survival analysis was carried out in terms of both crude and relative survivals.

Results: Overall incidence, increased over the 12 years considered, by an average of 6.8% per annum (P < 0.05). Only two cases of AIDS-related NHL were registered during this period. NHL incidence has increased slightly more for males than for females, further widening the gap in incidence between the sexes. In terms of histological grade the increase in incidence was more pronounced for low-grade and high-grade NHL than for intermediate-grade NHL. The overall 5-year relative survival rate was 69.3%. In multivariate relative survival analysis, neither sex, age, period of diagnosis nor place of hospitalization were significant prognostic factors. Only place of residence, with RR 2.2 (1.41-3.42) for people living in rural areas compared to urban areas and histological type, according to the working formulation with RR 3.8 (2.22-6.61) for high-grade tumours compared to low-grade tumours, remained informative for prognosis.

Conclusions: Although incidence of NHL has increased in Côte-d'Or, this trend has remained independent of the AIDS epidemic. Contrary to the findings of clinical trials, the patients' survival in this population-based series has not been shown to have improved over the study period.