De novo malignancies after adult-to-adult living-donor liver transplantation with a malignancy surveillance program: comparison with a Japanese population-based study.

BACKGROUND

Organ transplant recipients have an increased incidence of malignancy. Race differences in a variety of malignancies are observed among the general population, but de novo malignancies after adult-to-adult living-donor liver transplantation (LDLT) have not been compared with those from a Japanese population-based study.

METHODS

The subjects were 360 adult LDLT recipients who survived more than 1 year after transplantation. An annual medical checkup and screening examinations were performed as follows: abdominal computed tomography or magnetic resonance imaging, upper gastrointestinal endoscopy, and total colonoscopy and immunochemical fecal occult blood test every 1 to 2 years. Complete blood count, liver function tests, and several tumor markers were checked every 1 to 3 months after LDLT.

RESULTS

Mean follow-up period was 7.5±3.4 years. During the follow-up period, 27 de novo malignancies were diagnosed in 26 recipients. Colorectal cancer was the most commonly detected malignancy. The overall mortality of the recipients with de novo malignancies was similar to the findings of the Japanese general population-based study (standardized mortality ratio=0.9). Overall, the incidence of cancer was significantly higher in transplant recipients than in the Japanese general population (standardized incidence ratio=1.8). The 5-year estimated survival rate of recipients with de novo malignancies was 81% and those of recipients without malignancies was 93% (P<0.0001).

CONCLUSIONS

Colorectal malignancies predominated in Japanese liver transplant recipients. Although de novo malignancies correlated with a poor prognosis, the standardized mortality ratio was 0.9 compared with that of subjects of a Japanese population-based study.