Abstract
OBJECTIVE: To investigate prognostic factors of more than 10 years of survival for liver cancer patients after liver transplantation. METHODS: From May 2000 to May 2007, a total of 134 liver cancer patients who underwent liver transplantation in the Department of Hepatobiliary Surgery, Peking University People's Hospital, were continuously and retrospectively enrolled. The patients included 120 males and 14 females. There were 124 cases (92.5%) of primary hepatocellular carcinoma, 9 cases (6.7%) of cholangiocarcinoma, and 1 case of mixed hepatocellular carcinoma and cholangiocarcinoma. Patients with perioperative death were excluded. Follow-up was performed until May 31st, 2017 or the time of death. According to the data on postoperative survival time, patients were divided into a < 10 years group (81 cases) and a ≥ 10 years group (53 cases). Patients' clinical data were recorded and analyzed, including alpha-fetoprotein (AFP) level (≥ 400 µg/L or < 400 µg/L), number of tumor lesions (< 3 or ≥ 3), tumor size (≤ 5 cm or > 5 cm), vascular tumor thrombus (large blood vessel or non-large blood vessel), and histological differentiation degree. The Kaplan-Meier method was used to calculate survival rates. The log-rank method was used to compare the differences between survival curves. The Cox proportional hazards regression model was used to perform multivariate analyses of possibly influential factors. RESULTS: (1) Follow-up was conducted with all 134 liver cancer patients after liver transplantation. The follow-up periods were 1-201 months, with a median of 18 (8.75, 132.5) months. The Kaplan-Meier survival analysis results showed that the 1-year, 3-year, 5-year, and 10-year cumulative survival rates were 70.3%, 48.6%, 46.8%, and 46.8%, respectively. (2) The differences in the age of patients, the incidence rate of AFP ≥ 400 µg/L, tumor histological differentiation, vascular tumor thrombi, tumor lesion size, and number of tumor lesions between two groups were all statistically significant (all P < 0.01). (3) The cumulative survival rates were different in AFP (log-rank χ(2) = 13.428), histopathologic differentiation (log-rank χ(2) = 33.592), large blood vessel tumor thrombi (log-rank χ(2) = 36.470), tumor lesion size (log-rank χ(2) = 39.835), and number of tumor lesions (log-rank χ(2) = 47.016), and there were statistically significant differences between groups (all P < 0.01). (4) Multivariate Cox proportional hazards regression analyses showed that ≥ 3 tumor lesions [hazard ratio (HR) = 2.879, 95% confidence interval (CI) 1.566-5.422], tumor lesion size > 5 cm (HR = 2.682, 95% CI 1.382-5.366), large blood vessel tumor thrombi (HR = 1.831, 95% CI 1.010-3.341), and poor histological differentiation (HR = 2.150, 95% CI 1.372-3.394), were risk factors affecting the 10-year survival of liver cancer patients after liver transplantation (all P < 0.05). CONCLUSION: Tumor size, tumor number, large blood vessel tumor thrombi, and low tumor differentiation were all found to be independent risk factors affecting the 10-year survival rate after liver transplantation in liver cancer patients.