Prognostic Significance of The Diameter of Superior Rectal Vein For Locally Advanced Rectal Cancer

Abstract Objectives: The purpose of this study was to evaluate the association between the diameter of the superior rectal vein (dSRV) and prognosis in patients with locally advanced rectal cancer (LARC).Methods and materials: This retrospective study included 420 patients with LARC who received neoadjuvant therapy followed by total mesorectal resection (TME) from December 2014 to July 2017. The dSRV was measured before treatment. The maximal χ2 method was employed to determine the dSRV threshold of 3.6 mm based on the difference in disease-free survival, and then to divide the patients into 2 groups. The propensity score matching method (PSM) was used to balance the individual characteristics between the two groups. Kaplan–Meier curves and adjusted Cox models were used to determine the relationship among the baseline characteristics and overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS) and local recurrence-free survival (LRFS).Results: During a median follow-up of 45 months, 7 patients had relapse (1.60%), and 71 had distant metastasis (16.90%). Kaplan–Meier survival curves showed that patients with a dSRV > 3.60 mm had better survival (dSRV > 3.60 mm vs. ≤ 3.60 mm: 3-y MFS: 87.70% vs. 68.20%, P < 0.001; 3-y DFS: 85.50% vs. 64.20%, p < 0.001; 3-y OS: 91.90% vs. 82.20%, p=0.005). The multivariate Cox regression analysis after adjusting the covariates and the multivariate Cox regression analysis after performing PSM showed that the dSRV was an independent prognostic factor for MFS, DFS and OS.Conclusion: The dSRV measurement is valuable in predicting the prognosis of patients with LARC, and the prognosis of patients with a smaller dSRV seems to be poor.