Cancer morbidity and mortality after pediatric solid organ transplantation—a nationwide register study

Background The prevalence of malignancies after pediatric solid organ transplantation was evaluated in a nationwide study. Methods All patients who had undergone kidney, liver, or heart transplantation during childhood between the years 1982 and 2015 in Finland were identified. The inclusion criteria were age under 16 years at transplantation and age over 18 years at the last follow-up day. A total of 233 (137 kidney, 53 liver, and 43 heart) transplant recipients were enrolled. Controls ( n = 1157) matched by the year of birth, gender, and hometown were identified using the Population Register Center registry. The cancer diagnoses were searched using the Finnish Cancer Registry. Results Altogether 26 individuals diagnosed with cancer were found, including 18 transplant recipients. Cancer was diagnosed at a median of 12.0 (IQR 7.8–17.8) years after the transplantation. The transplant recipients’ risk for cancer was significantly higher when compared with the controls (HR 14.7; 95% CI 6.4–33.9). There was no difference for different graft types. Sixty-one percent of cancers among the transplant recipients were diagnosed at age older than 18 years. Conclusion The risk for cancer is significantly higher among young adults having undergone solid organ transplantation during childhood in comparison with population controls. Careful follow-up and attention to prevent cancers throughout adulthood are warranted.