Prognostic implications of resection margin status in distal pancreatectomy for pancreatic ductal adenocarcinoma.

BACKGROUND

Curative resection is a well known prognostic factor in pancreatectomy. However, definition and clinical significance of resection margin in distal pancreatectomy remains controversial.

METHODS

From 2010 to 2018, 203 patients with pancreatic cancer undergoing distal pancreatectomies were included. Patients were classified into three groups: R0-wide (tumor-free margin ≥1 mm), R0-narrow (0 mm < tumor-free margin <1 mm), and R1 margin (tumor-free margin = 0 mm). We also evaluated the prognostic impact of individual margins (transection, anterior, and posterior).

RESULTS

Patients with an R0-wide margin (36.6 %) exhibited superior 5-year disease free survival rate compared to those with R0-narrow (30.4 %, p = 0.059) or R1 margin (0.1 %, p = 0.014). However, in multivariate analyses, only R1 margin (hazard ratio [95 % confidence interval], 2.02 [1.32-3.12]; p = 0.001), unlike R0-narrow margin (1.17 [0.78-1.77]; p = 0.446), was linked to shorter overall survival compared to R0-wide margin. In multivariate analyses, posterior margin involvement was uniquely identified as a poor prognostic factor (1.83 [1.07-3.13]; p = 0.027).

CONCLUSIONS

The 0 mm rule seems more suitable than the 1 mm rule for predicting prognosis in performing distal pancreatectomy, and especially, achieving microscopically negative posterior margin is crucial.