Oral mucositis in recipients conditioned with oral busulphan for allogeneic hematopoietic stem cell transplantation.

Objectives: Oral mucositis (OM) is a side effect of intensive chemotherapy and has been reported to affect 75–100 % of hematopoietic stem cell transplantation (HSCT) recipients. The purpose of this study was to compare the incidence and severity of OM in patients conditioned with oral busulphan (BU) administered in a four-dose regimen (BU4) of 4x1 mg/kg/day for 4 days and in two-dose regimen of 4x1 mg/kg/day for 2 days.
Methods: The study involved 112 HSCT recipients, with hematological malignancies transplanted between 2007 and 2014 and conditioned with BU. Mean age of the patients was 49 years (range 11–72). Sixty (53 %) had BU2 and 52 BU4 regimen. Clinical features of OM were recorded from day −3 before up to day +25 after HSCT using the WHO scoring system.
Results: Overall, 90 % of the patients developed OM of any severity, which peaked on day 10-11. The mean OM score was 1.8. BU4 conditioning was correlated with significantly higher total OM score (8.8 ±4.6) from day 9 to12 compared to BU2 (5.4 ±3.9), (hazard ratio (HR) = 1.63, (95% CI) 1.33-2.01, p<0.001).
Conclusions: The incidence and severity of oral mucositis was lower in patients conditioned with two-dose BU regimen. Further investigations on the relationship of other conditioning regimens on OM are needed.