Salivary Her2/neu Levels in Differentiation of Oral Premalignant Disorders and Oral Squamous Cell Carcinomas

Background: Oral squamous cell carcinoma (OSCC) is thought to develop from precancerous dysplastic lesionsthrough multistep processes of carcinogenesis involving activation of oncogenes and loss of tumor suppressorgenes. The human epidermal growth factor receptor 2 (Her-2/neu [erbB-2]), a cell membrane glycoprotein, is agrowth factor receptor that has receptor tyrosine kinase activity. Her2/neu activation plays a central role in cellproliferation and survival. It has been shown that overexpression of Her2/neu increases the rate of cell divisionand growth, leading to precancerous changes. The aim of the present study was to compare the serum andsalivary Her2/neu levels between cases with premalignant and malignant oral lesions. Materials and
Methods:Fasting blood samples and unstimulated saliva by passive drooling were collected from three groups of healthycontrol (n=20), premalignant disorder (PMD) (n=20) and OSCC (n=25) subjects. The HER2 extracellulardomain (HER2 ECD) levels were measured using ELISA.
Results: The levels of serum Her2/neu showed nosignificant differences between any of the groups but on the other hand salivary Her2/neu levels were found tobe significantly (p<0.05) higher when compared between control (median 68.7 pg/ml, range: 21.5 - 75.8) andOSCC (median 145.6 pg/ml, range: 45.1-191.1). A similar trend was observed when comparing between PMD(median 43.3, range: 22.1 -94.7) and OSCC with a statistical significance of p<0.05.
Conclusions: Our studyprovided evidence of increased salivary Her2/neu in OSCC when compared to PMD and control which was notthe case for serum levels. This suggests that probably Her2/neu is not highly amplified as in breast cancer so asto be reflected in serum. Since saliva is in local vicinity of the OSCC, even a mild increase might be mirrored. Onthe whole, this study proposes Her2/neu as marker for distinguishing premalignant and malignant conditions.