Introduction: Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver and is responsible for up to 90% of all liver tumors. Liver transplantation remains the best option for patients with HCC. This study aimed to determine the impact of the histopathological features of the primary tumor to the long-term outcome of liver transplants for HCC.
Materials and Methods: Among 554 liver transplants performed between 1988 and 2016, only 61 was for the treatment of HCC. All histopathological prognostic criteria such as tumor grade, tumor size, the number of tumor nodules, the presence of lymphovascular invasion (LVI), and tumor necrosis were reevaluated. Patients classified into 2 groups; Group 1: patients who underwent LT within Milan criteria, and Group 2: patients who underwent LT beyond Milan criteria. Also, we divided Group 2 patients into 2 subgroups; Group 2a: tumors with favorable histologic features, Group 2b: tumors with unfavorable histologic characteristics. The mean follow-up time was 89.7±47 months.
Results: The histopathological mean tumor diameter was found 3.2 ±2.1 cm (1-9 cm) in 61 (M/F: 52/9) patients. Total 24 recipients died because of HCC at a mean time of 38.8 ±25 months posttransplant. The disease-free survival found to decrease with the increasing degree of grade and tumor size (p<.01). A tumor size >5 cm showed significant correlation with tumor recurrence and lower survival (p<.05).Patients who had LVI and also tumor necrosis tended to show lower survival (p<.01). The mean survival of Group 1 and Group 2 were 111.4±42 and 72.5±43.7 months, respectively. Overall 10-year survival was 76% and 43% for Group 1 and Group 2, respectively (p<.05). Overall 10-year survival was 75% and 28% for Group 2a and Group 2b, respectively (p<.01).
Overall 10-year survival rates of Group 1 and Group 2a were similar to each other (p>.05).Whereas patients in Group 2b with unfavorable histology showed poorer prognosis compared to patients who did not have these histopathological parameters (p<.01).
Discussion: Based on our results; we propose an algorithm to evaluate HCC for the decision of transplant. If HCC radiologically classified as “within Milan”, transplantation could be the treatment modality. If HCC classified as “beyond Milan”, a liver biopsy should be performed. If the histopathological characteristics were favorable, the treatment modality should be the same as tumors classified “within Milan”. If the tumor has unfavorable histologic characteristics, transplantation option could be still beneficial and curative for at least 50% of the patients in 5 years and 28% of the patients in 10 years.
Conclusion: Tumor biology is the most critical parameter that predicts the survival of patients with HCC and the histopathological parameters must take part in the selection criteria of the patients for LT.