Risk factors for recurrence of radically resected mucinous colorectal adenocarcinoma

Abstract

Background Local recurrence and distant metastasis are major challenges to overcome in order to improve the survival of patients with colorectal cancer (CRC) after surgery. Mucinous adenocarcinoma (MA) is a subtype of CRC associated with a higher incidence of local extension and worse survival compared to non-mucinous adenocarcinoma, but few studies have investigated predictors for poor clinical outcome of MA. Therefore, we aimed to elucidate the predictors for local recurrence and remote metastasis of MA after surgery.Methods This study retrospectively analyzed 162 patients with mucinous colorectal adenocarcinoma (MAC) after radical resection. Analysis variables included demographics, clinical indicators, pathologic stage, surgical procedure, adjuvant therapy, and recurrence. Univariate and multivariate analyses were performed to investigate the risk factors for local and distant tumor relapse.Results A total of 162 patients (86 male) with a mean age of 58.26 years were included; 70.37% of patients had colonic tumors, and 29.63% had rectal tumors. The 5-year disease-free survival (DFS) rates for these patients were as follows: 100% for TNM stage I, 71.2% for stage II, and 47.8% for stage III. Five-year DFS rates of MAC, colonic and rectal MA were 62.0%, 65.8%, and 51.7%, respectively. Local recurrence occurred in 38 patients (23.5%) and distant metastasis in 33 patients (20.4%). In univariate analysis, predictors for local recurrence of MAC were intra-operative blood loss (p=0.004, OR=1.005), intra-operative transfusion (p=0.002, OR=5.179), and N2 stage (p=0.000, OR=4.643), and predictors for distant metastasis were male sex (p=0.035, OR=2.410), CA199 (p=0.011, OR=1.004), CEA (p=0.020, OR=1.010), intra-operative blood loss (p=0.022, OR=1.003), T4 stage (p=0.007, OR=4.125), and N2 stage (p=0.018, OR=3.4). In multivariate analysis, predictors for local recurrence of colorectal MA were intra-operative transfusion (p=0.04, OR=4.175) and N2 stage (p=0.000, OR=5.291), and predictors for distant metastasis were male sex (p=0.049, OR=2.410), CA199 (p=0.02, OR=1.003), and T4 stage (p=0.007, OR=4.006).Conclusions Intra-operative transfusion and N2 stage were significant predictors for local recurrence. Male sex, CA199, and T4 stage were significant predictors for distant metastasis. Knowledge of the risk factors for postoperative recurrence provides a basis for logical approaches to treatment and follow-up of mucinous colorectal adenocarcinoma.