Outcomes after solid organ transplantation in survivors of childhood, adolescent and young adult cancer: A population-based study

Background Cancer treatment can lead to organ toxicity requiring solid organ transplant (SOT). Transplant teams must evaluate the appropriateness of SOT in survivors of childhood, or adolescent/young adult (AYA) cancer. Methods Children treated at a provincial (Ontario, Canada) pediatric center for any cancer between 1986-2021, and AYA (15-21 years) treated in an adult center for four common cancer types between 1992-2012, were identified using population-based databases. Outcomes were determined by linkage to administrative databases. Transplanted cancer survivors (cases) were matched 1:2 to SOT recipients without a prior cancer (controls). Post-SOT overall survival (OS), subsequent cancers, severe cardiovascular disease and graft loss/death were compared between groups. Results Among 16,533 cancer survivors, 52 received a SOT: 13 liver, 18 kidney, 11 lung, and 10 heart. Median age at SOT was 18 (IQR 14-27). Transplanted cancer survivors experienced lower 10-year post-SOT OS than controls (67.7 vs. 86.0%; p = 0.003). 10-year cumulative incidence of developing another de novo malignancy was 8.6%, similar to the incidence of first cancers among controls (12.9%; HR 1.05, p = 0.91). 10-year cumulative incidence of primary cancer recurrence was 10.5%. Cases (excluding heart transplants) were at risk for graft loss/death (HR = 2.00, 95% confidence interval 1.01-3.94), but not severe cardiovascular disease (HR = 1.10, CI 0.50-2.41). Conclusion Survivors treated with SOT had inferior survival than SOT recipients without a cancer history, but most achieved long-term cancer-free survival. These data can inform decisions around the suitability of cancer survivors for SOT.