Acute myeloid leukemia following solid organ transplantation: entity or novelty?

Due to the rarity of the disease, the characteristics of acute myeloid leukemia following solid organ transplantation (post-transplant AML; PT-AML) are unclear; furthermore, it is not known for certain whether PT-AML is a separate entity or not. We provide a systematic review of all previously reported cases of PT-AML in the English literature (n = 51). 45% of cases occurred after renal transplantation, and 72% were males. The median age at diagnosis of AML was 50 yr, with a median transplant-to-AML interval of 3.8 yr and a rapid decline in incidence after 5 yr. 26% of patients were asymptomatic at the time of presentation, and 42% were pancytopenic. M0/M1/M2, M3, M4/M5, and M6/M7 subtypes comprised 17%, 25%, 39%, and 19% of all cases, respectively. 36% of patients had unfavorable cytogenetic risk disease. The median overall survival was only 3 months. We observed several transplant-specific features: (i) The transplant-to-AML interval follows two very different patterns between renal vs. liver transplant patients. (ii) All 4 cases of donor cell leukemia occurred after liver transplant. (iii) Unfavorable risk disease was marginally significantly more common among renal compared with liver transplant patients (P = 0.057). Our results suggest that PT-AML is a separate entity with distinct characteristics, which need to be investigated further in future research. Heavy post-transplant immunosuppression likely plays a key role in the pathogenesis of PT-AML.