ABSTRACT
Objective:To investigate the value of counting microvessel density (MVD) and lymphatic vessel density (LVD) in predicting distant metastasis of pancreatic cancer within 1 year after surgery.Methods:The clinicopathological data of 47 patients with pancreatic cancer who underwent surgery in Laibin People's Hospital from January 2020 to December 2021 were retrospectively analyzed. The patients were divided into non-metastasis group( n=24) and metastasis group( n=23) according to whether distant metastasis occurred during 1-year follow-up. Immunohistochemistry was used to detect the CD 34 expression in microvascular epithelial cells and D2-40 level in lymphatic epithelial cells from pancreatic cancer tissues. MVD and LVD in cancer tissues and adjacent normal tissues were counted. The relationship between MVD and LVD in cancer tissues and clinicopathological characteristics such as gender, age, tumor diameter, tumor differentiation, lymph node metastasis, vascular invasion, nerve invasion and tumor stage were analyzed. The receiver operating characteristic curve (ROC) was drawn and the area under the curve (AUC) was calculated to evaluate the value of MVD and LVD in predicting distant metastasis of pancreatic cancer within 1 year after surgery. The effects of MVD and LVD on the distant metastasis rate of pancreatic cancer within one year after operation were evaluated. Univariate and multivariate logistic regression were used to analyze the independent influencing factors for distant metastasis of pancreatic cancer within 1 year after surgery. Results:MVD and LVD in metastatic cancer tissues were higher than those in adjacent normal tissues [(72.52±9.73) vs (51.73±7.95)/400 times field of view, (23.78±6.87) vs (14.00±5.66)/400 times field of view]. MVD and LVD in the non-metastasis group were also higher than those in the adjacent normal tissues [(63.20±6.52) vs (54.79±5.80)/400 times field of view, (16.25±5.15) vs (13.62±5.03)/400 times field of view], and all the differences were statistically significant ( P<0.05). MVD in cancer tissue was significantly increased in patients with tumor diameter ≥2 cm, lymph node metastasis, vascular invasion and high TNM stage ( P<0.05), and LVD was significantly increased in patients with tumor diameter ≥2 cm, lymph node metastasis, moderate and low differentiation, vascular invasion, nerve invasion and high TNM stage ( P<0.05). The AUC values of MVD and LVD in predicting distant metastasis of pancreatic cancer within 1 year after surgery were 0.799 (95% CI 0.659-0.939) and 0.803(95% CI 0.676-0.929), and the cut-off values were 70.5 and 20.5/400 times field of view, respectively. The sensitivity was 73.9% and 69.6%, and the specificity was 87.5% and 83.7%. The cumulative distant metastasis rate within 1 year after operation in high MVD and high LVD groups was significantly higher than that in low MVD and low LVD groups ( P<0.05). Multivariate logitic regression analysis showed that tumor diameter ≥2 cm ( OR=1.757, 95% CI 1.536-3.846, P<0.05), lymph node metastasis ( OR=2.364, 95% CI 1.036-4.175, P<0.05), high MVD ( OR=4.345, 95% CI 1.245-3.736, P<0.05) and high LVD ( OR=3.637, 95% CI 1.426-4.035, P<0.05) were independent risk factors for distant metastasis of pancreatic cancer within 1 year after surgery. Conclusions:Increased MVD and LVD in pancreatic cancer tissues are independent influencing factors for distant metastasis within 1 year after surgery, which can be used to predict whether patients have distant metastasis within 1 year after surgery.