Incidence, clinical characteristics and survival of malignant lymphomas: a population‐based study from a cancer registry in northern Italy

Abstract

We conducted a population-based study of peripheral lymphomas (PL) that had been diagnosed between 1997 and 2003 in the province of Modena, Italy, with the aim of providing updated incidence, clinical and survival data for these cancers. We evaluated the incidence patterns and time trends of 1582 cases of PL that had been reclassified according to the WHO classification of hematological malignancies. Data regarding clinical characteristics, treatment and outcome were also collected for each case. The World Age-Standardized Rate (ASR) was calculated as 13.4, 2.2 and 3.4 per 100,000 people for B-cell non-Hodgkin's lymphoma (NHL), T-cell NHL and Hodgkin's Lymphoma (HL), respectively, with an increase of 1.62% per year during the study period. The lymphoma subtype showing the highest incidence was found to be diffuse large B-cell lymphoma (DLBCL) with an ASR of 4.8. Compared with reports from other western countries, our series is characterized by a higher incidence of HL and indolent B-NHL in general, and of CLL/SLL (ASR = 3.3) and marginal zone NHL (ASR = 1.5), in particular, and also by a lower incidence of FL (ASR = 2). After a median follow-up of 54 months, the 5-year relative survival for the whole series was found to be 70% with a statistically significant improvement for cases diagnosed during 2002-2003 (from 66 to 74%; p = 0.03). Survival improvement within the study period was also evident for patients with DLBCL, HL and T-NHL. Our study provides a comprehensive description of both the epidemiological and clinical features of PL cases in Modena and our data also reflect the major advances in the curability of some histological subtypes of this disease. The usefulness of a population-based approach to better characterizing different lymphoma subtypes is also demonstrated.