Outcomes of patients diagnosed with de novo malignancies after lung transplantation

Background De novo malignancies are a major cause of late death following lung transplantation (LTx). Although previous reports from Japan have identified post-transplant lymphoproliferative disorder (PTLD) as the most common de novo malignancy, comprehensive long-term data on the spectrum, treatment, and outcomes of de novo malignancies remain limited. Methods We retrospectively reviewed the medical records of 413 patients who underwent LTx at our institution between April 2002 and December 2025 and analyzed the incidence, characteristics, and outcomes of de novo malignancies. Results De novo malignancy was diagnosed in 53 patients (12.8%), comprising 18 cases of PTLD and 37 cases of solid tumors (42 tumors in total). The cumulative incidence of PTLD was 3.1% at 1 year and remained stable thereafter, whereas the incidence of solid tumors increased steadily over time, reaching 16.8% at 10 years after LTx. PTLD and solid tumors showed distinct temporal patterns, with median times to onset of 8.0 months and 64.0 months, respectively. Regarding post-LTx lung cancer, five of the six cases (83.3%) originated in the native lung after single LTx. The 2-year overall survival after malignancy diagnosis was significantly higher in the curative treatment group than in the non-curative group (87.9% vs. 16.7%, p < 0.001). Conclusions Our findings demonstrate that the risk of solid malignancies continues to increase during long-term follow-up after LTx. The favorable outcomes observed among patients receiving curative treatment are considered to reflect earlier detection and better baseline patients’ condition, underscoring the importance of post-transplant cancer surveillance.