Clinical Significance of Primary Tumor Resection in Perihilar Cholangiocarcinoma with Positive Peritoneal Lavage Cytology

The prognostic impact of positive peritoneal lavage cytology (CY+) in patients with perihilar cholangiocarcinoma (PHC) remains unclear. The present study investigated the clinical significance of primary tumor resection of CY+ PHC.

We retrospectively evaluated 282 patients who underwent surgery for PHC between September 2002 and March 2022. The patients’ clinicopathological characteristics and survival outcomes were compared between the CY negative (CY−) resected (n = 262), CY+ resected (n = 12), and CY+ unresected (n = 8) groups. Univariate and multivariate analyses were performed to identify prognostic factors for overall survival.

The expected residual liver volume was significantly higher in the CY+ resected group (61%) than in the CY− resected (47%) and CY+ unresected (37%) groups (p = 0.004 and 0.007, respectively). The CY+ resected group had a higher administration rate of postoperative therapy than the CY− resected group (58% vs. 16%, p = 0.002). Overall survival of the CY+ resected group was similar to that of the CY− resected group (median survival time [MST] 44.5 vs. 44.6, p = 0.404) and was significantly better than that of the CY+ unresected group (MST 44.5 vs. 17.1, p = 0.006). CY positivity was not a prognostic factor according to a multivariate analysis in patients with primary tumor resection.

The CY+ resected group showed better survival than the CY+ unresected group and a similar survival to that of the CY− resected group. Resection of the primary tumor with CY+ PHC may improve the prognosis in selected patients.