De novo malignancy in heart transplant recipients: A single center experience in Japan

Background: Because of aggressive immunosuppression, heart transplant recipients have a high risk of de novo malignancy, which is a major cause of death and worse prognosis, regardless of the type. However, the impact of de novo malignancy on Japanese heart transplant recipients is unknown. Methods: We analyzed 103 Japanese heart transplant recipients over 18-years-old at the time of transplantation between April 1999 and April 2017. Patient characteristics and prognosis were compared between heart transplant recipients with or without de novo malignancy after heart transplantation (HTx). Additionally, univariate and multivariate analyses for the risk factors of de novo malignancy after HTx were performed. Results: De novo malignancy developed in 7 patients (6.8%; post-transplant lymphoproliferative disorders, n = 3; Bowen's disease, n = 1; colon cancer, n = 2; bladder cancer, n = 1). Follow-up time and previous antibody mediated rejection (AMR) ≥ grade 1 were risk factors of de novo malignancy after HTx in multivariate analysis (OR: 1.19, 95% CI: 1.00–1.42, p = 0.043; and OR: 10.7, 95% CI: 1.37–83.68, p = 0.038, respectively). History of malignancy was a potential risk factor, albeit not significant (OR: 23.05, 95% CI: 0.99–534.53, p = 0.071). The survival rates in patients with de novo malignancy was significantly lower than in those without de novo malignancy (3-year survival rate: 100% versus 67%, p = 0.0025). Conclusions: Long follow-up time and previous AMR ≥ grade 1 were risk factors of de novo malignancy after HTx. Japanese heart transplant recipients with de novo malignancy have worse prognosis; therefore, screening examinations are important for early diagnosis.