Association between lymphovascular invasion and lymph node metastases in colon cancer: A National Cancer Database analysis

Aim Lymphovascular invasion (LVI) is a well-known risk factor in colorectal cancer that is associated with a worse prognosis. The present study aimed to assess the characteristics of patients with LVI-positive colon cancer according to the status of nodal metastases and to study the association between LVI-nodal status and survival. Method This retrospective study assessed the association between LVI and lymph node metastases in colon cancer, using data from the National Cancer Database. Patients were classified according to the pathological N stage into pN0 and pN1-2. The risk factors for LVI were determined in each group using multivariable regression analyses. The primary outcome was LVI and the secondary outcome was 5-year overall survival (OS). A modification of the tumour, node, metastasis (TNM) staging system that incorporates LVI in each stage was proposed. Results The study included 357 724 patients (51.1% female, median age 70 years). LVI was detected in 11.6% and 52.5% of patients with node-negative and node-positive disease, respectively. The independent predictors of LVI in pN0 stage were poorly differentiated carcinomas (OR: 3.6, p < 0.001), undifferentiated carcinomas (OR: 3.3, p < 0.001), mucinous carcinomas (OR: 0.61, p < 0.001), and perineural invasion (OR: 4.2, p < 0.001). The independent predictors of LVI in pN1-2 disease were poorly differentiated carcinomas (OR: 2.36, p < 0.001), undifferentiated carcinomas (OR: 3.23, p < 0.001), and perineural invasion (OR: 3.33, p < 0.001). LVI was significantly associated with worse 5-year OS and the adverse survival impact of LVI was higher in pN1-2 disease (HR: 1.47, p < 0.001) than in pN0 disease (HR: 1.28, p < 0.001). When LVI was present, the 5-year OS was reduced by 1.5% in stage I, 5.6% in stage II, and 11.5% in stage III. Conclusion LVI was more prevalent in patients with colon cancer with lymph node metastases than in patients with node-negative disease. However, LVI was not detected in approximately half of patients with nodal disease. The adverse survival effect of LVI was proportional to the stage of colon cancer.