Salivary gland tumors: immunohistochemical study of EGF, EGFR, ErbB-2, FAS and Ki-67.

OBJECTIVE

To analyze the expression of ErbB-1 (Her-1 or EGFR), ErbB-2 (Her-2 or neu), ErbB-3 (Her-3) and ErbB-4 (Her-4) and their correlation in 3 different types of salivary gland tumors.

STUDY DESIGN

Immunohistochemical expression of epidermal growth factor (EGF), EGFR, ErbB-2, fatty acid synthase (FAS) and Ki-67 were analyzed in 41 pleomorphic adenoma (PA), in 30 mucoepidermoid carcinoma (MEC) and in 30 adenoid cystic carcinoma (ACC) and correlated with their histologic patterns.

RESULTS

EGF was more common in MEC and PA, but MEC had a higher percentage of strongly positive cases. EGFRc and EGFRm were both more frequent in MEC and ACC. Higher scores of ErbB-2c were observed in PA, followed by MEC and ACC. In contrast, higher scores of ErbB-2m were more common in MEC as compared to ACC and PA. FAS was most commonly found in PA and MEC. Moreover, MEC showed the highest percentage of strongly positive cases. Ki-67 was higher in MEC and ACC than in PA. From a correlation of immunomarkers with the histologic patterns, it was observed that cribriform ACC presented more expression of EGFR and high grade MEC showed a higher percentage of ErbB-2, FAS and Ki-67.

CONCLUSION

EGF, EGFR, ErbB-2 and FAS were commonly found and seem to be important in the tumorigenesis of salivary gland tumors, particularly in percentage of strongly positive cases. Ki-67 was higher in MEC and ACC than in PA. From a correlation of immunomarkers with the histologic patterns, it was observed that cribriform ACC presented more expression of EGFR and high grade MEC showed a higher percentage of ErbB-2, FAS and Ki-67.

CONCLUSION

EGF, EGFR, ErbB-2 and FAS were commonly found and seem to be important in the tumorigenesis of salivary gland tumors, particularly in MEC. (Anal Quant Cytol Histol 2009;31:280-287)