Incidence of metachronous peritoneal metastases for intrahepatic cholangiocarcinoma after curative resection: A single center cohort analysis.

Abstract

e16199 Background: The impact of metachronous peritoneal metastases (m-pm) on survival after curative resection for intrahepatic cholangiocarcinoma (iCCA) is poorly understood, while there is some knowledge to the occurrence of pulmonary and hepatic metastases. Studies are needed to analyze the impact of advanced metastatic disease for m-pm for iCCA after curative resection. Methods: At the Charité - Universitätsmedizin Berlin, a total of 1979 patients with the general diagnosis of cholangiocellular carcinoma were discussed in interdisciplinary tumor conferences from 2010 to 2022. Results: At the Charité - Universitätsmedizin Berlin, a total of 1979 patients with the general diagnosis of cholangiocellular carcinoma were discussed in interdisciplinary tumor conferences from 2010 to 2022. iCCA was present in 269 cases and proven histopathological results were documented at our hospital in 227 patients. Out of these, 209 patients underwent curative resection, while no advanced tumor disease leading to termination of the indicated operation were found. Two patients presented limited synchronous peritoneal metastases (s-pm) intraoperatively. The postoperative histopathological result presented N0-status in 113 patients and N+-status in 96 patients. Metachronous metastases were diagnosed in 17 patients after 103 months on average with a mean overall survival (OS) of 108 months. Regarding postoperative complications >3b Clavien-Dindo after the initial surgery one patient died in the early postoperative follow-up within the first 30 days. Complete radical resection (R0) was achieved in 133 patients, while R1-status was recorded in 28 patients. Furthermore seven m-pm patients additionally presented hepatic metastases, five m-pm patients pulmonary metastases, while one m-pm patient showed simultaneous hepatic and pulmonal metastases and one other m-pm patient developed even hepatic, pulmonal and osseous metastases. Neoadjuvant oncologic therapy was performed in two patients, adjuvant therapy was applied in six patients prior to the diagnosis of m-pm. Again, a total of five patients received palliative therapy after diagnosis of m-pm. Nevertheless, one patient underwent pulmonary metastectomy. Conclusions: The primary aim regarding the two s-pm patients was immediate postoperative surgical outcome without complications (>3a according to Clavien-Dindo) and was feasible, regarding the prognostic impact of s-pm for surgical resectability; curative resection seems to be an option. The primary aim for m-pm was OS, while promising outcomes were shown in this study.