Impact of tumor circumferential location on prognosis in mid-low rectal cancer: a propensity- score-matched analysis
10.3760/cma.j.cn441530-20250619-00230
- VernacularTitle:基于倾向性评分匹配探究直肠肿瘤环周位置对中低位直肠癌患者预后的影响
- Author:
Wendi JIANG
1
;
Shihao LI
;
Shuyuan LI
;
Zheng LOU
;
Wei ZHANG
Author Information
1. 海军军医大学第一附属医院肛肠外科，上海 200433
- Publication Type:Journal Article
- Keywords:
Rectal neoplasms, mid-low;
Circumferential location;
Local recurrence;
Circumferential resection margin
- From:
Chinese Journal of Gastrointestinal Surgery
2025;28(11):1267-1279
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the impact of circumferential tumor location (anterior wall, nonanterior wall, or circumferential) on circumferential resection margin (CRM) status, local recurrence, and survival in patients with mid-low rectal cancer.Methods:A retrospective cohort study was conducted using data from 696 patients with mid-low rectal adenocarcinoma who underwent surgery in the Department of Colorectal Surgery at the First Affiliated Hospital of Naval Medical University between December, 2018 and December, 2019. Based on MRI or contrast-enhanced CT findings, the rectal wall was divided into four quadrants: anterior, posterior, left, and right. Tumors were classified into three groups: anterior wall group ( n = 245), nonanterior wall group ( n = 286, tumors predominantly located on the posterior or lateral walls), and circumferential group ( n = 165, tumors involving ≥ 3/4 of the circumference). Propensity score matching (PSM) was used to balance baseline characteristics. Outcomes included pathological CRM positivity, local recurrence rate (LRR), overall survival (OS), and disease-free survival (DFS). Cox regression analysis was performed to identify risk factors for recurrence, and subgroup analysis was conducted in patients who did not receive neoadjuvant therapy. Results:After PSM, both the anterior and circumferential groups had significantly higher pathological CRM positivity rates compared to the nonanterior wall group ( P=0.040 and P=0.039, respectively). The median follow-up time was 64 months (range: 1-71 months). Compared to the nonanterior wall group, the anterior wall group also had a significantly higher 5-year LRR (8.8% vs. 2.3%, P=0.003), and significantly lower 5-year OS (80.7% vs. 91.6%, P=0.001) and DFS (76.6% vs. 84.6%, P=0.029). The circumferential group had a significantly higher 5-year LRR than the nonanterior wall group (11.4% vs. 3.8%, P=0.020), but no significant differences were observed in 5-year OS (81.8% vs. 89.5%, P=0.100) or DFS (70.7% vs. 78.3%, P=0.101). No significant differences were found between the anterior and circumferential groups in 5-year LRR (11.1% vs. 9.7%), OS (76.3% vs. 83.7%), or DFS (69.8% vs. 74.1%) either (all P>0.05). Cox univariate analysis and multivariate analysis identified anterior wall tumors (HR=3.751, 95%CI: 1.373-10.215, P=0.010), circumferential tumors (HR=3.240, 95%CI: 1.109-9.466, P=0.032), pathological CRM positivity (HR=3.071, 95%CI: 1.144-8.245, P=0.026), and lymph node metastasis (HR=2.584, 95%CI: 1.192-5.601, P=0.016) as independent risk factors for LRR. Conversely, a greater distance from tumor to the anal verge (per 1 cm increase, HR=0.831, 95%CI: 0.712-0.970, P=0.019), and neoadjuvant therapy (HR=0.442, 95%CI: 0.204-0.957, P=0.038) were identified as independent protective factors against LRR. In patients who did not receive neoadjuvant therapy, locally advanced nonanterior wall tumors exhibited markedly low LRR (1.3% for pathological stage II-III, 1.6% for pT3-4 stage). Conclusion:Rectal tumors located in the anterior wall or involving the circumference are associated with higher CRM positivity rates, increased local recurrence, and poorer survival. These patients should be prioritized for neoadjuvant therapy. In contrast, nonanterior wall tumors have a low recurrence rate, and selective omission of neoadjuvant therapy may be considered for these cases.
