Clinical significance of bile duct margin carcinoma in situ in patients with distal cholangiocarcinoma undergoing pancreaticoduodenectomy.

BACKGROUND

The biological heterogeneity and oncological impact of R1 carcinoma in situ (R1cis) lesions in distal cholangiocarcinoma (DCC) remain unclear. This retrospective study evaluated the clinical significance of R1cis in patients with DCC undergoing pancreaticoduodenectomy (PD).

METHODS

We retrospectively analyzed 151 patients who underwent PD for DCC between 2005 and 2023, excluding those with in-hospital mortality or distant metastasis. Based on the final pathological diagnosis, patients were classified into three groups: final R0, final R1cis, and final R1inv (invasive carcinoma).

RESULTS

Fourteen patients (9%) had final R1cis and seven (5%) had final R1inv. The final R1cis group showed significantly worse overall survival (OS) than the final R0 group (median survival time: 34.3 vs. 114.7 months, p = 0.002). Preoperative and intraoperative analysis identified elevated preoperative CA19-9 (p < 0.001), preoperative modified Glasgow Prognostic Score (p = 0.038), and initial R1inv (p < 0.001) as independent predictors of poor OS. Postoperative analysis demonstrated that pancreatic invasion (p = 0.037), pT3/T4 (p = 0.023), final R1cis (p = 0.007), and final R1inv (p = 0.001) were independent prognostic factors. Recurrence occurred more frequently in the R1cis/R1inv group, with increased rates of both local and distant recurrence.

CONCLUSION

Final R1cis is an independent prognostic factor for poor survival in DCC after PD, highlighting the importance of achieving final R0 resection.