The impact of geographic proximity to transplant center on outcomes after allogeneic hematopoietic stem cell transplantation.

Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) need access to specialized care. We hypothesized that access to the transplant center after HSCT may be challenging for patients living in geographically distant areas, and that this would have an adverse effect on their outcome. We analyzed 1912 adult patients who underwent allogeneic HSCT at the Dana-Farber/Brigham and Women's Cancer Center (DF/BWCC) between 1996 and 2009 and who resided within 6 hours driving time of the institution. Driving time from primary residence to DF/BWCC based on zipcode was determined using geographic information systems. The median driving time (range) to DF/BWCC was 72 (2-358) minutes. When patients were stratified by driving time quartile, overall survival (OS) after HSCT was similar in the first year but worse after 1 year in patients in the top quartile (≥ 160 minutes driving time). In a landmark analysis of the 909 patients alive and free of disease at 1 year, 5-year OS was 76% and 65% for patients in the first (≤ 40 minutes) and fourth (≥ 160 minutes) quartiles, respectively (P = .027). This was confirmed in a multivariable analysis. The difference appeared to be mostly because of an increase in nonrelapse mortality. The number of visits to the transplant center between day 100 and 365 after HSCT declined significantly with increasing driving time to the transplant center, which was independently associated with worse survival. Long driving time to the transplant center is associated with worse OS in patients alive and disease-free 1 year after HSCT, independently of other patient-, disease-, and HSCT-related variables. This may be in part related to the lower frequency of post-HSCT visits in patients living farther away.