OP201: EGFR amplification in saliva of oral cancer patients: A pilot study

Abstract

Objectives We aim to examine EGFR, CCND1, TP53 and P16 expression in oral squamous cell carcinoma (OSCC) and pre-and post-operative saliva samples from the same patients. Materials and Methods 28 OSCC samples were used to assess EGFR, CCND1, TP53 and P16 protein expression in OSCC and paired adjacent normal mucosa, by immunohistochemistry (IHC), and EGFR amplification, by fluorescent in situ hybridization (FISH). Examination for TP53 mutation(s) on exons 5–8 by sequencing, HPV status using the Roche linear array, and EGFR copy number by quantitative real-time PCR was also performed. Saliva from 14 healthy controls and 27 oral cancer patients were analyzed for genetic changes in OSCC, and associated with clinicopathological data. Results EGFR protein over-expression was commonly found in OSCC and was associated with perineural invasion (p = 0.04) and advanced tumor grade (p = 0.03). EGFR copy number gains in OSCC were significantly associated with T3–T4 category (p = 0.04) and perineural invasion (p = 0.02). EGFR copy number was increased in OSCC and not significantly different from pre-operative saliva; EGFR copy number in saliva from healthy controls was significantly different from pre-operative saliva (p = 0.02). Conclusions Analysis of EGFR amplification in saliva could become useful for monitoring patients for recurrence or the appearance of a second primary tumor.