Epidermal growth factor receptor, MUC-1 and MUC-2 in bladder cancer

The aim of this study was to investigate the immunohistochemical expression of epidermal growth factor receptor (EGFR), mucin-1 (MUC-1) and mucin-2 (MUC-2) proteins in primary bladder carcinomas and to compare EGFR and MUC staining patterns with the histological findings, grade and stage of bladder carcinoma. Fifty-six surgical specimens obtained from superficial and deeply invasive bladder carcinomas were studied. Of the 56 bladder tumors 42 (75%) expressed EGFR, 34 (60.71%) MUC-1 and 15 (26.78%) MUC-2; while 7 tumors (12.5%) coexpressed MUC-1 and MUC-2 proteins. Immunohistochemical scores showed higher levels of EGFR than of MUC-1 (P <0.05) and MUC-2 (P = 0.000) and higher levels of MUC-1 than MUC-2 (P = 0.0010). EGFR and MUC-1 expression was stronger in high-grade tumors (grade 2/3) than in low-grade (grade 1/2) ones (P <0.05) and stronger in muscle invasive tumors (T2-T4) than in superficial (Ta-T1) ones. Linear regression showed a significant (P <0.05) correlation between EGFR and MUC-1 proteins, but no correlation between EGFR and MUC-2 or between MUC-1 and MUC-2. Immunohistochemical expression of EGFR, MUC-1 and MUC-2 increases as primary bladder carcinomas acquire a more aggressive phenotype. Differences in the distribution of EGFR and mucins within the urothelium may be of diagnostic and prognostic value. These antigens may be useful as markers for bladder malignancy.