A systematic review and meta‐analysis of pathologic complete response rates for patients with cholangiocarcinoma treated on liver transplant protocols

Background and Objectives Many heterogenous orthotopic liver transplant (OLT) protocols exist for patients with unresectable cholangiocarcinoma. Little is known about the incidence, predictors for, and the significance of achieving a pathologic complete response (pCR). Methods We performed a systematic review through September 2022 of the PubMed, Embase, and Web of Science databases. A random‐effect meta‐analysis was conducted to pool data across studies with reported pCR rates. Heterogeneity between treatment protocols was assessed via subgroup analysis. The pCR and 1‐, 3‐, and 5‐year recurrence‐free survival (RFS) and overall survival (OS) rates were extracted as outcomes of interest. Results A total of 15 studies reported pCR rates and were grouped by use of the Mayo protocol (4/15), stereotactic body radiation therapy (2/15), and an Other category (9/15). The pooled pCR rate among all studies was 32%. Both radiation technique and duration of CHT showed no significant association with pCR (p = 0.05 and 0.13, respectively). Pooled 1‐year RFS and OS after any neoadjuvant therapy and OLT was 80% (95% confidence interval [CI], 0.61–0.91), and 91% (95% CI, 0.87–0.94), respectively. There was no 1‐year OS difference detected among the three groups. pCR was not associated with OS in the meta‐regression. Pooled 3‐ and 5‐year OS among all studies was 72% and 61%, respectively. Conclusions The pooled incidence of pCR was 32%. Differences in radiation technique did not appear to influence pCR rates and upon meta‐regression, pCR was not a surrogate marker for survival.