The prognostic factors for survival after curative resection of distal cholangiocarcinoma: perineural invasion and lymphovascular invasion

The purpose of this study was to elucidate the prognostic factors for distal cholangiocarcinoma after curative resection, and to assess the significance of perineural invasion (PNI) and lymphovascular invasion (LVI) as prognostic factors. A retrospective analysis of 91 patients who underwent radical surgery for distal cholangiocarcinoma between March 2004 and October 2011 was performed. We analyzed the survival rate and prognostic factors affecting the survival. The overall 1-, 3- and 5-year survival rates were 84.1, 49.7 and 38.9 %, respectively. In the univariate analysis, the prognostic factors influencing the survival were the histological differentiation, lymph node (LN) involvement and TNM stage. In the multivariate analysis, LN metastasis was the only independent prognostic factor. Although patients with PNI tended to show poorer survival, it was not a statistically significant factor (3- and 5-year OS; 62.0 and 54.6 % vs. 42.8 and 30.9 %, P = 0.166). In the patients with a total lymph node count (TLNC) of 11 or less, PNI was a significant prognostic factor; however, it was not a significant factor in the patients with a TLNC over 11. Overall, the LVI had no influence on the patient survival. LN metastasis was the only significant prognostic factor after the curative resection of distal cholangiocarcinoma. In cases where adequate dissection was performed, it appeared that the PNI and LVI had no influence on the survival.