Prognostic Characteristics of Patients With Colorectal Cancer Who Have Benign Mesenteric Lymph Node Enlargement: A Multi-institutional Cohort Study

BACKGROUND: The characteristics of patients with colorectal cancer who have benign mesenteric lymph node enlargement are not well documented. OBJECTIVE: The aim of this study is to assess the clinical and prognostic significance of benign mesenteric lymph node enlargement in patients with colorectal cancer. DESIGN: This is a prospective cohort study. SETTING: This study was conducted at multitertiary institutions. PATIENTS: We included 601 patients with stage 0, I, and II colorectal cancer in Tianjin, Shandong, and Zhejiang from January 2010 to April 2014. Patients underwent curative surgery and were separated into 2 groups by the presence of benign mesenteric lymph node enlargement: the enlargement group (n = 275) and the control group (n = 326). MAIN OUTCOME MEASURES: Univariate log rank and multivariate Cox regression analyses were constructed to identify risk factors for recurrence and mortality. RESULTS: The risk of recurrence in the enlargement group after curative resection was significantly lower than in the control group, with the 1-, 3-, and 5-year disease-free survival rates being 97.1%, 91.6%, and 86.9% in the enlargement group and 95.7%, 86.2%, and 78.2% in the control group (p = 0.004). The postoperative 1-, 3-, and 5-year overall survival rates were 99.6%, 94.9%, and 90.5% in the enlargement group and 99.4%, 91.4%, and 82.1% in the control group (p = 0.001). Patients in the enlargement group had a higher percentage of patients at a younger age, family tumor history, right-sided tumors, and larger tumor size compared with the control group. For patients in the enlargement group, no significant correlation was observed between the number of enlarged lymph nodes and disease-free survival or overall survival (p = 0.113 and 0.386). Adjusted Cox regression model showed that benign mesenteric lymph node enlargement was an independent prognostic risk factor for both disease-free survival (HR, 0.587; 95% CI, 0.399-0.861; p = 0.007) and overall survival (HR, 0.506; 95% CI, 0.328-0.779; p = 0.002). LIMITATIONS: No immunological results could be compared with clinicopathological findings. CONCLUSIONS: The study indicates that benign mesenteric lymph node enlargement can be a useful positive factor in predicting recurrence and long-term survival concerning patients with colorectal cancer.