Prediction of prognosis in gallbladder carcinoma by mucin and p53 immunohistochemistry

Mucin core proteins are known to be present in various organs and are specifically expressed with carcinogenesis and closely associated with the prognoses of various malignant tumors in the digestive tract such as colorectal cancer. The present study evaluated correlations between mucin and p53 expression and prognosis of gallbladder cancer using surgically resected tissue specimens from 26 patients with gallbladder carcinoma surgically treated at our hospital. Immunohistochemical staining was performed using MUC1, MUC2, and p53 monoclonal antibody. The level of antigen expression in the lesion was classified into four stages: none(-), slight(+), moderate (++), and severe (+++). According to the UICC classification, histopathological grading, levels of T, N, and M factors, and tumor stages were compared with regard to the correlations with mucin and p53 expression. All cases were classified into two groups according to the results of mucin immunohistochemistry: group A (MUC1, >={++}; and MUC2, <=+) and group B (MUC1, < ++; or MUC2, > +). Postoperative survival periods were compared between the two groups and p53-positive and -negative groups. Neither histological grading nor T factor correlated with mucin or p53 expression, respectively. Moreover, neither N factor nor M factor correlated with mucin or p53 expression. Furthermore, stage grouping did not correlate with mucin or p53 expression. However, when the correlation between the postoperative survival period and mucin expression was evaluated, the mean postoperative surgical period was significantly shorter in Group A than in Group B (1.02 years in Group A vs 2.92 years in Group B; P = 0.016). There was no relationship between postoperative survival period and p53 positivity. Mucin expression was independent of various tumor growth factors and clearly reflected the prognosis of gallbladder cancer. Because the relative malignancy of gallbladder cancer could be evaluated by examining the level of glycoprotein expression in tumor tissue, mucin could be a more important marker than p53 for predicting prognosis in gallbladder carcinoma using surgically resected tissue specimens.