Disparity in survival outcome after hematopoietic stem cell transplantation for hematologic malignancies according to area of primary residence

Abstract

We evaluated whether or not a patient's area of primary residence is an independent risk factor for overall survival (OS) after HLA-identical sibling or autologous hematopoietic stem cell transplantation (HSCT). This retrospective cohort study included patients who underwent autologous (n = 1739) or HLA-identical sibling (n = 267) HSCT to treat a hematologic malignancy between 1983 and 2004 at the University of Nebraska Medical Center. Primary area of residence, using the patient's zip code, was categorized as either urban or rural (including isolated, small rural, or large rural) according to the Rural Urban Commuting Area Codes (RUCA) classification system. An association between area of primary residence and survival was examined using Cox proportional hazards regression analysis while adjusting for patient-, disease-, and treatment-related variables. Patients from rural areas who received autologous HSCT had a higher relative risk of death (relative risk = 1.18; P = .016) than urban patients who underwent the same procedure. Survival rates in patients from rural and urban locations are as follows: 1 year, 73% vs 78% (P = .04); 5 year, 48% vs 54% (P = .012). We failed to detect a significant difference in the risk of death according to primary area of residence in the HLA-identical sibling HSCT cohort, although this may be from lack of statistical power. Our findings suggest that the primary location of a patient's residence may be an independent risk factor for survival after HSCT.