Expression of MK-1 and RegIV and its clinicopathological significances in the benign and malignant lesions of gallbladder

Background: To study the expression of MK-1 and RegIV and to detect their pathological significances in benign and malignant lesions of gallbladder. Methods: The expression of MK-1 and RegIV was detected by immunohistochemical method in paraffinembedded sections of surgical resected specimens from gallbladder adenocarcinoma (n = 108), peritumoral tissues (n = 46), adenomatous polyp (n = 15), and chronic cholecystitis (n = 35). Results: The positive rate of MK-1 or RegIV expression was significantly higher in gallbladder adenocarcinoma than that in peritumoral tissues (chi(2)(MK-1) = 18.76, P < 0.01; chi(2)(RegIV) = 9.92, P < 0.01), denomatous polyp (chi(2)(MK-1) = 9.49, P < 0.01; chi(2)(RegIV) = 8.59, P < 0.01) and chronic cholecystitis (chi(2)(MK-1) = 24.11, P < 0.01; chi(2)(RegIV) = 19.24, P < 0.01). The positive cases of MK-1 and/or RegIV in the benign lesions showed moderately-or severe-atypical hyperplasia of gallbladder epitheli. The positive rates of MK-1 were significantly higher in the cases of well-differentiated adenocarcinoma, no-metastasis of lymph node, and no-invasiveness of regional tissues than those in the ones of differentiated adenocarcinoma, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma (P < 0.05 or P < 0.01). On the contrary, the positive rates of RegIV were significantly lower in the cases of well-differentiated adenocarcinoma, no-metastasis of lymph node, and no-invasiveness of regional tissues than those in the ones of differentiated adenocarcinoma, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma (P < 0.05 or P < 0.01). Univariate Kaplan-Meier analysis showed that decreased expression of MK-1 (P = 0.09) or increased expression of RegIV (P = 0.003) was associated with decreased overall survival. Multivariate Cox regression analysis showed that decreased expression of MK-1 (P = 0.033) and increased expression of RegIV (P = 0.008) was an independent prognostic predictor in gallbladder adenocarcinoma. Conclusions: The expression of MK-1 and/or RegIV might be closely related to the carcinogenesis, clinical biological behaviors, and prognosis of gallbladder adenocarcinoma.