Factors influencing completion of cancer therapy in heart transplant recipients with de novo malignancies.

e23058 Background: Among recipients of solid organ transplants, heart transplant recipients are at highest risk of developing malignancies due to high levels of immunosuppression required to prevent graft rejection. Previous studies have evaluated the role of various immunosuppressive medications, such as mTOR inhibitors and cyclosporine, in prevention and development of malignancies in this population. However, after development of malignancy, factors influencing completion of cancer therapy in these patients remain unclear. In this single-center retrospective study, we investigate cancer-directed therapy among heart transplant recipients who developed malignancies and identify factors associated with completion of therapy. Methods: We conducted a single-center retrospective analysis of heart transplant recipients aged ≥18 years between January 1992 and January 2024 who developed de novo malignancies post-transplant. Patients with benign tumors or insufficient cancer-related data were excluded. Data collected included therapy completion status, ECOG performance status (PS), cancer type and stage, time from transplant to malignancy, immunosuppression adjustments, and mTOR inhibitor use. Statistical analysis was conducted using Fisher’s exact test. Results: 84 patients were included in this study. A majority of patients had non-melanoma skin cancers (n = 49, 58.3%), were stage I at diagnosis (n = 44, 52.4%), and had an ECOG PS of 1 at diagnosis (n = 48, 57.1%%). Median time from transplant to malignancy was 57.5 months. Surgery was the most common first-line treatment (n = 59, 70.2%), followed by chemotherapy (n = 20, 23.8%) and radiation (n = 17, 20.2%). Post-malignancy, 29.8% (n = 25) received mTOR inhibitors, and 28.6% (n = 24) underwent immunosuppression dose reductions. Overall, 89.3% (n = 75) completed therapy. Completion rates were higher among patients with ECOG PS ≤1 (p = 0.003), Stage ≤ II malignancies (p < 0.001), and those who underwent surgical treatment (p = 0.002). These associations persisted after excluding non-melanoma skin cancers. mTOR inhibitor use did not significantly impact completion rates (p = 0.263). Conclusions: In heart transplant recipients with malignancies, better ECOG PS, earlier stage, and surgical treatment were associated with higher completion rates of cancer-directed therapy. mTOR inhibitor was not associated with higher completion rates.