Prognostic impact of molecular analyses in adenoid cystic carcinomas of the salivary gland

Background: Adenoid cystic carcinoma (ACC) of the salivary gland is a gener ally slow-growing but highly malignant neoplasm with a remarkable capacity for recurrence. Prognosis is greatly influenced by the histological subtype (tubular, cribriform or solid), presence of tumour at the margins, anatomi c size, and lymph node metastases. However, none of these parameters has pr oven to be an unequivocal predictor of disease activity. Therefore, the cur rent study was undertaken to investigate the prognostic value of molecular markers. Patients and Methods: Samples from 22 patients, including 4 patien ts with recurrent disease, were included in the study. By means of immunohi stochemistry, the staining pastern of p53, bcl-2, P-glycoprotein, glutathio ne S-transferase, and topoisomerase as well as sequence analyses of p53 wer e performed. These molecules were chosen because of their proven associatio n with poor prognosis and therapy resistance in other malignancies. Results : Homozygous p53 mutations were found in all of the 4 recurrent tumors. The other proteins were detected in some tumors, but showed no correlation wit h histological subtype or recurrence of tumor. Conclusion;The results of th e current study emphasize the prognostic value of a p53 alteration as an in dependent prognostic marker. Further, it could be demonstrated for the firs t time that proteins known for their association with radio- and chemothera py resistance can be overexpressed in some ACCs suggesting that those molec ules could influence the outcome of new therapeutical approaches.