Characteristics and Prognosis of Colorectal Cancer after Liver or Kidney Transplantation

Background: The purpose of this study was to evaluate the characteristics and prognosis of de novo CRC patients who underwent liver or kidney transplantation.

Methods: We retrospectively reviewed the medical records of 66 de novo CRC patients selected from 8,734 liver transplant (LT) or kidney transplant (KT) recipients. We analyzed characteristics and survival outcomes of de novo CRC patients and sporadic CRC patients who underwent radical surgery with stage I-III in Asan Medical Center between 2005 and 2016. Survival outcomes were analyzed via the 1:4 matching method.

Results: The standard incidence ratio (SIR) of de novo CRC in KT recipients is 1.67 in men and 2.54 in women. That in LT recipients is 3.10 in men and 2.25 in women. Compared with sporadic CRC patients, de novo CRC patients had more colon cancer than rectal cancer (p=0.041). In 9 patients (13.6%), CRC was diagnosed within one year after transplantation, 21 patients (31.8%) were diagnosed between 1-5 years, and the remaining 36 patients (54.6%) were diagnosed thereafter. There were no significant differences in recurrence-free survival and overall survival between the two groups (p=0.211 and p=0.324, respectively).

Conclusions: The risk of developing de novo CRC in transplant recipients was higher than in the general population. The survival outcome of de novo CRC was no different compared with the sporadic CRC. Therefore, regular surveillance is essential for timely diagnosis and treatment for transplantation patients. A large prospective study for an intense CRC surveillance program in transplantation patients is needed.