INTRODUCTION
In 1969, Drs. Penn and Starzl first published their observation of five renal transplant patients who developed malignant lymphomas and cautioned about the risk of malignancy in transplant patients on long-term immunosuppression.1 Since that time, many have published on the increased incidence of posttransplant malignancy compared to the general population, with immunosuppressive therapy and oncologic viral infections suggested as two causative etiologies.2–5 These malignancies include lymphomas and the transplant-specific entity of post-transplant lymphoproliferative disorder (PTLD), as well as solid-organ malignancies. Post-transplant patients are at particularly increased risk of skin cancers, Kaposi sarcomas, and genitourinary carcinomas.3,6
Heart transplant patients are at even higher risk than other solid organ transplant recipients due to greater need for immunosuppression.7,8 At the same time, post-heart transplant survival has improved over time with improvements in immunosuppression, infectious disease prophylaxis, perioperative care, and postoperative monitoring. The median survival for patients undergoing heart transplants between 2002 to 2009 is 12.5 years, an improvement from 10.5 years in 1992-2001.9 The risk of post-transplant de novo malignancy (DNM) poses a threat to further survival improvement. Previous literature has suggested that calcineurin inhibitors specifically increase the risk of malignancy, whereas mycophenolate mofetil (MMF) and mTOR inhibitors decrease the risk.8,10–12 We sought to examine rates of malignancy development in adult heart transplant patients, compare them to the general population, and identify potentially modifiable risk factors.