Prognostic significance of the degree of lymphatic vessel invasion in locally advanced, surgically resectable pancreatic head cancer: A single center experience

Little is known concerning the prognostic significance of the degree of lymphatic vessel invasion in pancreatic head cancer. To address this gap in knowledge, we retrospectively examined 60 patients with locally advanced, surgically resectable pancreatic head cancer who underwent pancreaticoduodenectomy and lymph node (LN) dissection. All cases were histopathologically diagnosed as ductal adenocarcinoma, stage II (25 pT3N0 cases, 35 pT3N1 cases). The following variables were investigated: age; sex; neoadjuvant therapy; adjuvant therapy; tumor size; tumor grade; invasion into the serosa, retropancreatic tissue, duodenum, bile duct, portal venous system and perineural area; cut margins; LN metastasis; and the number of invaded lymphatic vessels (LVI-score). Univariate analysis demonstrated that LN metastasis and an LVI-score ≥5 were significantly associated with poor disease-free survival. Multivariate Cox regression analysis confirmed that LN metastasis and an LVI-score ≥7 were significantly associated with poor disease-free survival. Additionally, LVI-scores ≥9 and ≥10 were comparable to or surpassed the significance of LN metastasis based on the hazard ratio. Univariate analysis demonstrated that tumor size >30 mm, duodenal invasion, LN metastasis and an LVI-score ≥2 were significantly associated with poor overall survival. Multivariate Cox regression analysis confirmed that LN metastasis and LVI-scores ≥9 and ≥10 were significantly associated with poor overall survival, and an LVI-score ≥10 was comparable to or surpassed the significance of LN metastasis based on the hazard ratio. Our study strongly suggests that a high degree of lymphatic vessel invasion is associated with a poor prognosis in patients with locally advanced, surgically resectable pancreatic head cancer.