Treatment of secondary myelodysplastic syndrome after heart transplantation with chemotherapy and nonmyeloablative stem-cell transplantation.

Background. Treatment of secondary cancer after solid-organ transplantation is difficult because of coexisting medical conditions, reduced organ function, or advanced age in most patients. Methods. A 60-year-old man developed treatment-related myelodysplastic syndrome (refractory anemia with excess blasts in transformation) 10 years after orthotopic heart transplantation. After remission induction with chemotherapy, the patient received peripheral blood stem cells from his HLA-identical ABO-mismatched (A→O) sister after conditioning with fludarabine and low-dose total-body irradiation (200 cGy). Postgrafting immunosuppression consisted of mycophenolate mofetil and cyclosporine A. Results. The patient experienced little toxicity from the conditioning regimen and achieved complete donor chimerism within 65 days. Five months after transplant, the patient developed pure red cell aplasia that resolved after treatment. At present, he is alive in complete remission with 100% donor hematopoiesis 940 days after stem-cell transplantation. Conclusions. Allogeneic blood stem-cell transplantation using minimal conditioning is a new, promising treatment option for patients with hematologic malignancies after solid-organ transplantation.