Abstract 480: Analysis of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of 178 primary locally advanced oral squamous cell carcinoma cases: the prognostic implication

Abstract

Abstract Background: Oral Squamous Cell Carcinomas comprise of a heterogeneous tumor cell population with of varied molecular characteristics; which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. Study design: A retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population Aim: • To evaluate the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas. • To assess the reliability of this panel of biomarkers for prognostication and treatment planning of locally advanced oral squamous cell carcinomas • To identify a potential biomarker that can predict the tumor response to treatment. Patient Selection: All patients who were diagnosed with locally advanced oral squamous cell carcinomas cases between the year 2009 and 2013 were reviewed. These patients were treated with radiotherapy and adjuvant chemotherapy. The maximum duration of follow-up was 5 years and the minimum follow-up time is 1 ½ years. Material and Methods: Formalin fixed paraffin embedded tumor blocks of (n = 178) of histopathologically diagnosed cases locally advanced oral squamous cell carcinomas were selected. The areas where the tumor cells appeared most aggressive were identified in the Hematoxylin and Eosin stained tissue sections of these cases. The corresponding areas were identified in the tumor blocks and two cores of 2 mm diameter for each case were obtained and tissue microarray blocks were constructed. Four microns thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53 and Bcl-2 and cyclin D1 and p16. The expression of these markers by the tumor cells was evaluated in a semi quantitatively. The dat Results: In this cohort, EGFR was the most expressed in 150/178 (84%) of the cases. The expression of EGFR was significantly associated with p53 (p = .012), and with cyclin D1 (p = .011). Kaplan Meier analysis showed a significant association (p = .038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (Unadjusted IRR -95% CI 2.08 (1.03, 4.5), Adjusted IRR- 2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Conclusion: Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients. Citation Format: Monica C. Solomon, Mammadipuli Vidyasagar, Donald Fernandes, Vasudeva Guddattu. Analysis of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of 178 primary locally advanced oral squamous cell carcinoma cases: the prognostic implication. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 480.