Her-2/neu overexpression in muscle-invasive urothelial carcinoma of the bladder: prognostic significance and comparative analysis in primary and metastatic tumors

Abstract

Purpose: The prognostic significance of Her-2/neu overexpression in muscle-invasive urothelial carcinoma of the bladder is largely unknown. Accurate determination of Her-2/neu overexpression may have therapeutic importance.

Experimental design: Eighty consecutive cases of muscle-invasive urothelial carcinoma of the bladder treated by radical cystectomy with available follow-up were analyzed. In each case, one representative section was stained with anti-Her-2/neu. Staining was graded as 1 = faint/equivocal, 2 = moderate, and 3 = strong and was considered positive if > or =2. In those cases with a metastasis, the stain was also performed in the metastatic tumor. Results were correlated with survival.

Results: Twenty-two (28%) cases were considered Her-2/neu-positive in the primary tumor, and 17 of 32 (53%) were considered Her-2/neu-positive in the lymph node metastasis. Median survival for Her-2/neu-positive primary tumors was 33 months, compared with 50 months for Her-2/neu-negative cases (P = 0.46). Similarly, Her-2/neu overexpression in the lymph node metastasis did not predict survival. Sixty metastatic urothelial carcinomas were further studied by comparing Her-2/neu expression in the primary tumor with that of the lymph node and/or distant metastasis. Forty-five percent of Her-2/neu-negative primary tumors had a Her-2/neu-positive lymph node metastasis, whereas only one case (8%) of Her-2/neu-positive primary tumors was Her-2/neu-negative in the lymph node metastasis (P = 0.009). Similarly, 67% of Her-2/neu-negative primary tumors had a Her-2/neu-positive distant metastasis, whereas no Her-2/neu-positive primary tumor was negative in the metastasis (P = 0.429).

Conclusions: Her-2/neu overexpression in primary or metastatic tumor did not predict survival in this cohort of muscle-invasive tumors. Overexpression in the primary tumors consistently predicts overexpression in a distant or regional metastasis. However, some Her-2/neu-negative primary tumors may show overexpression in their corresponding metastasis. Her-2/neu analysis in a metastasis may be necessary to accurately determine Her-2/neu status in metastatic bladder urothelial carcinoma.