Proliferating cell nuclear antigen and c-erbB-2 oncoprotein expression in adenoid cystic carcinomas of the salivary glands.

BACKGROUND: Adenoid cystic carcinoma (ACC) of the salivary gland shows a variable clinical course. It would be helpful to discover reliable biologic markers in the management of patients with ACC. METHODS: We examined proliferating cell nuclear antigen (PCNA) and c-erbB-2 oncoprotein expression on 30 cases of ACC of the salivary glands. The immunohistochemical results, and size, location, and histologic grade of the tumors were compared with the clinical outcome of the patients. RESULTS: Mean PCNA positivity of ACCs was 15%, and was higher in solid than in cribriform/tubular areas. High PCNA value was significantly correlated with shorter disease-free and overall survival of the patients with ACC. c-erbB-2 overexpression was observed in only five cases, focally in cribriform/tubular areas. High histologic grade, which was determined by the presence of solid components, showed a trend toward shorter survival. Size and location of ACC were not associated with patient outcome. CONCLUSIONS: The present study indicates that PCNA score may be one of the most useful prognostic factor of ACC.