Role of routine lymph node dissection alongside resection of intrahepatic cholangiocarcinoma: Systematic review and meta-analysis.

Background: The global incidence of intrahepatic cholangiocarcinoma (ICCA) is soaring. Due to often delayed presentation, only a narrow spectrum of the disease is usually surgically resectable. To more accurately stage the disease, reduce recurrence, and improve overall survival, surgical teams are increasingly performing intraoperative lymph node dissection (LND) as well. This procedure has its associated morbidity, while there is no consensus or formal guidelines on its role in this setting. Hence, there is a need to better delineate the evidence for performing LND alongside surgical resection of the ICCA.

Aim: To perform a systematic review and meta-analysis on the role of LND in improving prognostication and survival post-resection of ICCA.

Methods: We performed a systematic literature search using Pubmed, Medline, Embase, and the Cochrane Library, for all studies involving LND, ICCA, and surgical resection using several keywords, Medical Subject Headings (MeSH) tags, and appropriate synonyms. All clinical studies comparing curative intent resection of ICCA with LND resection without LND were included, while single-arm case series, studies with insufficient data, and duplicates were excluded. We included all English-language studies from the different academic databases up till early December 2022. The primary outcome measures were set for overall survival (OS) and disease-free survival (DFS).

Results: This systematic review and meta-analysis included 15 studies that fulfilled the selection criteria comprising 11413 patients with surgically-resectable ICCA, of whom 6424 (56.3%) underwent hepatectomy with LND while the remainder underwent hepatectomy only. In patients who underwent LND, on average, 27.7% of the resected lymph nodes were positive for metastatic disease. Overall, the results showed that performing LND did not significantly improve OS or DFS. However, the effect of LND on OS showed a degree of variability by geographical region, in Eastern and Western countries. As LND is increasingly being performed, further time-based analysis was undertaken to identify time-dependent changes in the role of LND. An increasing adoption of LND was not associated with improved OS. Furthermore, no roles were identified for neoadjuvant/adjuvant chemotherapy or increasing lymph node retrieval in improving OS either.

Conclusion: LND might aid in staging, prognosticating, and deciding further management of resected ICCA, but does not improve OS and DFS and is unsuitable for high-risk patients unlikely to benefit from further treatments.