Can the Limits of Liver Transplantation Be Expanded in Perihilar Cholangiocarcinoma?

The most common location of cholangiocarcinomas is the perihilar region with a frequency of 50-70%. Current standard treatment for perihilar cholangiocarcinomas (pCCA) is surgical resection. In cases where resection treatment is possible, the 5-year survival rate is 8-40%. However, using a very strict patient selection, neoadjuvant radiochemotherapy (NRCT), staging laparotomy, and liver transplantation (LT), called "the Mayo protocol," 5-year survivals of up to 70% in pCCA were reported. This treatment protocol clearly requires an intensive workforce and a harmonious multidisciplinary approach. Reoperation and retransplantation rates are high, which is a reflection of the NRCT. Multicenter studies, systemic reviews, and meta-analysis results, comparing both resection and LT in pCCA treatment and evaluating only LT results, pointed to LT with strict patient selection and full compliance with the treatment. The results of centers experienced in LT are better in treating pCCA. According to Mayo clinical data, histopathological diagnosis could not be obtained in half of the patients with pCCA before NRCT was given. This situation can be explained by the necrosis of the tumor due to the effect of NRCT and the fact that the tumor cannot be detected in the explant liver. This situation raises the following questions: did all patients actually have pCCA? Were these good results due to some patients not having pCCA? The 5-year survival rate was worse in patients with a pathological diagnosis than those without a pathological diagnosis. However, interestingly, recurrence rates were statistically similar in both groups. There was no difference in survival between LT and resection in the R0N0 subgroup in de novo pCCA. There are still many issues that need to be addressed and corrected in pCCA, which is one of the most problematic indications for LT. Significant success has been achieved with NRCT, staging laparotomy, and LT in selected patients with pCCA developing on the basis of PSC or early-stage unresectable de novo pCCA. It can be expected that new NRCT modalities will provide better survival by expanding the indications for LT in pCCA.