Subsequent malignancies after allogeneic hematopoietic stem cell transplantation.

We evaluated 979 patients for the development of post-transplant lymphoproliferative disease (PTLD) and solid malignancies after allogeneic hematopoietic stem cell transplantations (allo-HSCT) as a late complication. We found 15 (1.5%) subsequent malignancies; three of these malignancies were PTLD, and twelve were solid tumors. The median time from allo-HSCT to the development of PTLD was 9 (3-20) months and that from allo-HSCT to the development of solid tumors was 93 (6-316) months. The cumulative incidence of evolving subsequent malignancy in patients was 1.3% (±0.5 SE) at 5 years and 3.9% (±1.2 SE) at 10 years. The cumulative incidence of developing subsequent malignancy in patients with benign hematological diseases as the transplant indication was 7.4%±4.2 SE at 5 years. More subsequent malignancy developed in patients having ≥1 year chronic graft-vs-host disease (GVHD; 3.7% in ≥1 year chronic GVHD and 0.7% in <1 year chronic GVHD patient groups, P=.002). Subsequent epithelial tumor risk was higher in ≥1 year chronic GVHD patients than <1 year (3.7% vs 0.1%, P<.001). In multivariate analysis, benign hematological diseases as transplant indication (RR: 5.6, CI 95%: 1.4-22.3, P=.015) and ≥1 year chronic GVHD (RR: 7.1, 95% CI: 2.3-22.5, P=.001) were associated with the development of subsequent malignancy.