Expressive levels of MUC1 and MUC5AC and their clinicopathologic significances in the benign and malignant lesions of gallbladder

Abstract

Objective: This article is intended to make a study on the expressive levels of mucin core proteins (MUC1 and MUC5AC) and detect their clinicopathologic significances in the benign and malignant lesions of gallbladder.

Methods: EnVision immunohistochemical method for determining the expressions of MUC1 and MUC5AC was used in routinely paraffin-embedded sections of surgically resected specimens from gallbladder adenocarcinoma (n = 108), peritumoral tissues (n = 46), adenoma (n = 15), and chronic cholecystitis (n = 35).

Results: The positive rate of MUC1 expression was significantly higher in gallbladder adenocarcinoma than that in peritumoral tissues (χ(2) = 16.49, P < 0.01), adenoma (χ(2) = 7.40, P < 0.01), and chronic cholecystitis (χ(2) = 28.57, P < 0.01), while the positive rate of MUC5AC expression was significantly lower in gallbladder adenocarcinoma than that in peritumoral tissues (χ(2) = 12.83, P < 0.01), adenoma (χ(2) = 4.22, P < 0.05), and chronic cholecystitis (χ(2) = 20.25, P < 0.01). The positive cases of MUC1 and the negative ones of MUC5AC in the benign lesions showed moderate- or severe-dysplasia of gallbladder epithelium. The positive rates of MUC1 were significantly lower in gallbladder adenocarcinomas with maximal diameter of mass <2 cm, no metastasis of lymph node, and no invasiveness of regional tissues (P < 0.05 or P < 0.01) than those in gallbladder adenocarcinomas with maximal diameter of mass >2 cm, metastasis of lymph node, and invasiveness of regional tissues (P < 0.05 or P < 0.01). However, the positive rates of MUC5AC were significantly higher in the highly differentiated adenocarcinoma with maximal diameter of mass <2 cm than those in the low-differentiated adenocarcinoma with maximal diameter of mass ≥2 cm. Univariate Kaplan-Meier analysis showed that increased expression of MUC1 (P = 0.064) or decreased expression of MUC5AC (P = 0.017) was associated with decreased overall survival. Multivariate Cox regression analysis showed that decreased expression of MUC5AC (P = 0.008) was an independent prognostic predictor to gallbladder adenocarcinoma.

Conclusions: The expression of MUC1 and MUC5AC might be closely related to the carcinogenesis, clinical biological behaviors, and prognosis of gallbladder adenocarcinoma.