CD56-Positive Acute Myeloid Leukemia Has Inferior Outcome After Allogeneic Hematopoietic Stem Cell Transplantation

CD56-positive AML patients have more extramedullary infiltrate and inferior outcomes when treated with intensive chemotherapy. We evaluate the outcomes between CD56 positive and negative AML patients after allogeneic hematopoietic stem cell transplantation.

Forty-one AML patients underwent hematopoietic stem cell transplantation at our institute between August 2002 and September 2010. Two of them received autologous transplantation and the other 39 were allotransplant. We analyze the survival and relapse rates when transplanted in complete remission between CD56 positive and negative patients.

Among these 41 patients, 13 were CD56 positive (M/F 7/6 and median age 34.9 years) with 7 of them (53.8%) had extramedullary involvement; 28 were CD56 negative (M/F 14/14) and median age 42.7 years) with 2 of them (7.1%) had extramedullary involvement. Two-year and five-year overall survivals for all patients were 48% and 40%, respectively. For CD56 positive and negative patients, 2-year overall survivals were 22% and 54%, respectively. There were 30 patients undergoing transplant in complete remission with 8 CD56 positive and 22 CD56 negative, and the relapse rates after transplant were 75.0% and 31.8%, respectively, (p = 0.049). High risk cytogenetics were found in 5 out of 13 CD56 positive patients and 5 out of 17 available cytogenetics CD56 negative patients, which is of no statistically different.

Even following the most intensive treatment hamatopoietic stem cell transplantation, CD56-positive AML patients still have more relapse rate, and poor survival which is independent of cytogenetic risk. This indicated CD56 positivity is truly a poor prognostic factor and needs to consider allogeneic hematopoietic stem cell transplantation early on remission achieved and earlier immunosuppressants withdrawal is mandatory for those who allotransplant.

No relevant conflicts of interest to declare.