Risk of Acute Myeloid Leukemia Among Solid Organ Transplant Recipients

Patients receiving solid organ transplants experience increased risk of subsequent hematologic malignancies, particularly post-transplant lymphoproliferative disorder and non-Hodgkin lymphoma, likely in relation to infection with oncogenic viruses and pharmacologic immunosuppression to prevent graft rejection. However, less is known about the risks for myeloid neoplasms such as acute myeloid leukemia (AML).

We linked data from the US Scientific Registry of Transplant Recipients, a national database of solid organ transplantation, with 13 state and regional cancer registries to obtain cancer occurrence among 175,732 solid organ transplants during 1987–2008. The observed number of patients developing AML was compared to that expected in the general population of the 13 registry areas using standardized incidence ratios (SIRs).

AML was identified in 107 solid organ transplant recipients (13.8 cases/100,000 person-years), a rate that was nearly three times higher than expected in the general population [SIR=2.9, 95% confidence interval (CI) 2.4–3.5]. Excess risks were highest among children and young adults but remained significantly elevated among individuals receiving a solid organ transplant prior to age 65 years (SIR, 95%CI: <20 years=9.3, 3.4–20.2; 20–34 years=6.3, 3.2–11.3; 35–49 years=3.9, 2.6–5.6; 50–64 years=2.5, 1.9–3.3; 65+years=1.7, 0.9–2.9). Patients receiving liver or heart and/or lung transplants had higher risks than patients receiving kidney transplants (liver=4.1, 2.9–5.7; heart and/or lung=4.0, 2.7–5.7; kidney=2.0, 1.4–2.7). Risks also were higher among individuals receiving a second solid organ transplant than those receiving their first (second=6.8, 3.5–11.9; first=2.7, 2.2–3.3). Excess risks persisted throughout the 22-year period and showed no trend over time.

In the largest population-based study of transplant-related malignancies conducted to date, we demonstrate that patients receiving solid organ transplants have substantially elevated risk for subsequent AML. Future investigations should evaluate the possible role of specific immunosuppressive medications in the etiology of post-transplant AML.

No relevant conflicts of interest to declare.