Secondary oral cancer following hematopoietic cell transplantation.

The aim of this retrospective study was to determine the incidence and the clinical outcome of secondary oral cancer (SOC) and to assess potential risk factors in a large cohort of patients (n = 908), who received allogeneic hemopoietic cell transplantation (HCT) either for a malignant (n = 733) or nonmalignant hematologic disease (n = 175). The median follow-up of 438 transplant survivors was 17 years. Twelve patients developed SOC at a median of 13.5 years since HCT and at a median age of 47 years. The 35-year cumulative incidence function of SOC development was 3.47%. In univariate analysis, factors associated with increased incidence of SOC were reduced intensity conditioning and chronic graft-versus-host disease (cGvHD). On multivariate analysis, nonmalignant disease and duration of oral cGvHD ≥15 months were independent risk factors for SOC development. Nonmalignant disease recipients had 3.94× higher than expected rate of SOC (95% confidence interval, 1.50-10.39%, p = 0.0055). Recipients whose oral cGvHD persisted for more than ≥15 months had 58.6× higher than expected rate of SOC (95% confidence interval, 13.3-258.1%), p < 0.0001). This study demonstrates that oral cGvHD and a diagnosis of nonmalignant hematologic disease are strong risk factors in the SOC development.