Background : Several studies have reported that solid organ transplant recipients have a high risk for malignant tumors because the suppressed immune system fails in preventing malignant transformations. De novo malignancy after transplantation is the most common cause of death in the late period after liver transplant (LT). This study investigated the clinical significance of de novo malignancy after LT, and it is the largest study based in Korea to report long-term follow-up results associated with de novo malignancy after LT.

Methods : The study population was 2,598 adults who underwent LT from 1988 to March 2023. Data were retrospectively collected, and medical charts and data from the Ministry of Public Administration and Security were reviewed to examine the causes of death and de novo malignancy status.

Results : Of the 2598 recipients, 173 developed de novo cancer and 63 were died. Of 1296 hepatocellular carcinoma (HCC) patients, 35 died, and of 1302 non-HCC patients, 28 died with de novo cancer. De novo malignancy was the main cause of death at 5 years after LT but was not in the initial 5 years. In Korea the most common cancers that developed after LT were lymphoma 33 (%) and gastric cancer 26 (%), and De novo HCC in non-HCC cases was found in 3 patients.

Conclusions : De novo malignancy is a key factor affecting long-term survival after LT. Therefore, regular screening and education are important for improving long-term survival and quality of life in these patients after LT.