Objectives: The aim of the study was to determine the impact of socioeconomic status on relapse-free survival (RFS) in patients with Hodgkin's disease.
Methods: A number of factors were analyzed for their impact on relapse-free and overall survival in Hodgkin's disease using Cox regression. These factors included socioeconomic status (as defined by education and income), different treatment modalities and established clinical risk factors [e.g. age at diagnosis, stage of disease, involvement of three or more lymph nodes, presence or absence of a large mediastinal mass, E stages or elevation of erythrocyte sedimentation rate (ESR)]. The study used an initial sample of 126 patients recruited between 1969 and 1995 and a larger sample of 218 patients (recruited until 2002). Clinical data on disease and treatment characteristics were collected from medical records.
Results: In a univariate analysis, the following parameters had impact on RFS: treatment modality (combined treatment resulted in an improved RFS compared with patients treated with chemo- or radiotherapy alone), educational status and income. The 5- and 10-yr relapse-free survival rates were found to increase with decreasing educational level and decreasing average income per month. These results were significant in the initial and total samples and were also significant using multivariate analysis (hazard ratio for highest vs. lowest education group: 5.88; 95% confidence interval 1.87-18.52; for highest vs. lowest income group: 4.36; 95% confidence interval 1.35-14.05).
Conclusion: Hodgkin's disease appears to be a striking exception from the usual positive correlation between high socioeconomic status and favorable treatment outcome in patients suffering from tumor. It is suggested that future studies on tumor genetics and biology and more detailed analysis of further socioeconomic parameters may be useful in clarifying this observation.