Outcome of children who experience disease relapse following allogeneic hematopoietic SCT for hematologic malignancies.

Relapse after allogeneic hematopoietic SCT (HSCT) carries a poor prognosis and is a common cause of death. Outcomes of children who relapse post HSCT are not well known. In this retrospective multicenter study we included 532 patients who underwent allogeneic HSCT and examined the outcomes of 160 patients (30%) who relapsed. Treatment options after relapse included (i) palliative therapy with non-curative intent (n=43), (ii) salvage chemotherapy (without a second HSCT, n=55) or (iii) salvage chemotherapy followed by a second HSCT (n=62). Sixty two patients underwent a second HSCT. The 1-year disease-free survival (DFS) for those given palliative therapy, chemotherapy alone and who underwent a second transplant was <1%, 9% and 50% (P=<0.0001), respectively. The DFS at 1 and 2 year was 50% and 35%, respectively, among the patients who received a second transplant versus 9% and 2% in those who did not (P=<0.0001). In multivariable analysis longer time to relapse (P=0.04) and undergoing a second HSCT (P<0.001) were associated with improved outcome. Withdrawal of immunosuppressive therapy, followed by curative intent chemotherapy should be offered to all patients who relapse after an allogeneic HSCT. A second HSCT should be considered, especially in patients who respond to salvage chemotherapy.