Role of social status and social environment on net survival in patients with chronic lymphocytic leukemia: A high-resolution population-based study.

ABSTRACT

BACKGROUND: The prognostic roles of social status and social environment in chronic lymphocytic leukemia have been highlighted in some solid tumors but remain unclear in hematological malignancies. The objective of this study was to evaluate the influence of individual social status (with socioprofessional category, SPC) and social environment (with European deprivation index, EDI) on net survival in a high-resolution population with CLL. METHODS: We included CLL patients from the Regional Register of Hematological Malignancies in Normandy belonging to the French Network of Cancer Registries (Francim). The SPC variable was divided into 5 categories farmers, craftsmen, higher employment, intermediate employment, and workers/employees. Net survival was used to estimate the excess of mortality in CLL independent of other possible causes of death using French life tables. Net survival was estimated with a nonparametric method (Pohar-Perme) and with a flexible excess mortality hazard model. Missing data were handled with multiple imputation. RESULTS: A total of 780 patients were included. The median follow-up was 7.9 years. The crude survival at 10 years was 50%, and the net survival at 10 years was 80%. In multivariate analysis, a higher age (EHR 1.04 [1.01-1.07]), being a craftsman (EHRcraftsmen/higher.employment 4.15 [0.86-20.15]), being a worker or an employee (EHRworkers.employees/higher.employment 3.57 [1.19-10.7]), having a Binet staging of B or C (EHR 3.43 [1.84-6.42]) and having a lymphocyte count > 15 G/L (EHR 3.80 [2.17-6.65]) were statistically associated with a higher risk of excess mortality. EDI was not associated with excess mortality (EHR 0.97 [0.90-1.04]). CONCLUSION: Socioprofessional category was a prognostic factor for an excess of mortality in CLL. Craftsmen and workers/employees shared a worse prognosis than workers with higher employment. The social environment was not a prognostic factor. Further work should be performed to explore causal epidemiologic or biological factors and other hematological malignancies.