Role of Intraoperative Assessment of Proximal Bile Duct Margin Status and Additional Resection of Perihilar Cholangiocarcinoma: Can Local Clearance Trump Tumor Biology? A Retrospective Cohort Study

Recommendations on maximising the clinical value of tissue in the management of patients with intrahepatic cholangiocarcinoma

Background & Aims

Patients with intrahepatic cholangiocarcinoma can now be managed with targeted therapies directed against specific molecular alterations. Consequently, tissue samples submitted to the pathology department must produce molecular information in addition to a diagnosis or, for resection specimens, staging information. The pathologist's role when evaluating these specimens has therefore changed to accommodate such personalised approaches.

Methods

We developed recommendations and guidance for pathologists by conducting a systematic review of existing guidance to generate candidate statements followed by an international Delphi process. Fifty-nine pathologists from 28 countries in six continents rated statements mapped to all elements of the specimen pathway from receipt in the pathology department to authorisation of the final written report. A separate survey of 'end-users' of the report including surgeons, oncologists, and gastroenterologists was undertaken to evaluate what information should be included in the written report to enable appropriate patient management.

Results

Forty-eight statements reached consensus for inclusion in the guidance including 10 statements about the content of the written report that also reached consensus by end-user participants. A reporting proforma to allow easy inclusion of the recommended data points was developed.

Conclusions

These guiding principles and recommendations provide a framework to allow pathologists reporting on patients with intrahepatic cholangiocarcinoma to maximise the informational yield of specimens required for personalised patient management.

Impact and Implications

Biopsy or resection lesional tissue from intrahepatic cholangiocarcinoma must yield information about the molecular abnormalities within the tumour that define suitability for personalised therapies in addition to a diagnosis and staging information. Here, we have developed international consensus guidance for pathologists that report such cases using a Delphi process that sought the views of both pathologists and 'end-users of pathology reports. The guide highlights the need to report cases in a way that preserves tissue for molecular testing and emphasises that reporting requires interpretation of histological characteristics within the broader clinical and radiological context. The guide will allow pathologists to report cases of intrahepatic cholangiocarcinoma in a uniform manner that maximises the value of the tissue received to facilitate optimal multidisciplinary patient management.

Role of Intraoperative Frozen Section Assessment of Proximal Bile Duct Margins and the Impact of Additional Re-Resection in Perihilar Cholangiocarcinomas

Intraoperative frozen section (FS) analysis to assess the bile duct margin status is commonly used to assess the completeness of resection during surgery for perihilar cholangiocarcinoma (pCCA) resection. However, the impact of additional re-section on the long-term outcome after obtaining an initial positive margin remains unclear. Patients diagnosed as pCCA on preoperative imaging and subjected to curative intent surgery from May 2013 to June 2021 with a minimum follow-up of 2 years were included. Intraoperative FS analysis of the proximal bile duct margin was performed in all patients. A positive margin was defined by the presence of invasive cancer. Out of the 62 patients with a preoperative diagnosis of pCCA on imaging, 35 patients were included for final analyses after excluding patients with inoperable disease (on staging laparoscopy or local exploration) and other/benign pathology on the final histopathology report. Out of the 35 patients, patients with postoperative 90-day mortality were excluded from the final survival analysis. FS analysis revealed an initial positive margin in 10 (28.5%) patients. Among 10 patients who underwent re-resection to achieve negative proximal margins, only 5 patients achieved a negative margin (secondary R0). An initial positive margin was associated with poor long-term outcomes. Median disease-free survival (DFS) and overall survival (OS) were 16 and 19.6 months for patients with an initial positive margin, but 36 and 58.2 months for patients with an initial negative margin, respectively (p = 0.012). The median DFS and OS were significantly lower for those with secondary R0 as compared to primary R0 (16 vs. 36 months for DFS, p = 0.117 and 19.6 vs. 58.2 months for OS, p = 0.027, respectively). An intraoperative FS positive proximal hepatic duct margin dictates poor long-term outcomes for patients with resectable pCCA. Additional resection has a questionable benefit on survival, when a secondary negative margin is achieved.

How to Determine Unresectability in Hilar Cholangiocarcinoma

Hilar cholangiocarcinoma is considered a biologically aggressive disease for which surgical resection remains the only curative treatment. Preoperative evaluation for resectability is challenging given tumor proximity to the porta hepatis, but minimal benefit and increased morbidity precludes recommendation for margin positive resection. This article reviews the determination of unresectability in hilar cholangiocarcinoma through discussion of the preoperative assessment, the intraoperative assessment, and key steps of surgical resection, as well as treatment options for unresectable tumors. Overall, evaluating patients preoperatively for resectability requires a multidisciplinary, holistic, and individualized approach to accurately determine resectability and optimize clinical outcomes for patients with hilar cholangiocarcinoma.

Essential updates 2021/2022: Update in surgical strategy for perihilar cholangiocarcinoma

Resection is the only potential curative treatment for perihilar cholangiocarcinoma (PHC); however, complete resection is often technically challenging due to the anatomical location. Various innovative approaches and procedures were invented to circumvent this limitation but the rates of postoperative morbidity (20%-78%) and mortality (2%-15%) are still high. In patients diagnosed with resectable PHC, deliberate and coordinated preoperative workup and optimization of the patient and future liver remnant are crucial. Biliary drainage is recommended to relieve obstructive jaundice and optimize the clinical condition before liver resection. Biliary drainage for PHC can be performed either by endoscopic biliary drainage or percutaneous transhepatic biliary drainage. To date there is no consensus about which method is preferred. The volumetric assessment of the future remnant liver volume and optimization mainly using portal vein embolization is the gold standard in the management of the risk to develop post hepatectomy liver failure. The improvement of systemic chemotherapy has contributed to prolong the survival not only in patients with unresectable PHC but also in patients undergoing curative surgery. In this article, we review the literature and discuss the current surgical treatment of PHC.