PDF file - 1.2MB, t of Supplemental Materials Supplemental Table 1. EDRN Cohort Characteristics by HPV Status Supplemental Table 2. EDRN Cohort Tumor Molecular Correlates by HPV Status Supplemental Figure 1. RPPA results were validated by immunoblotting analysis. Supplemental Figure 2. Representative EGFR IHC stained tumor cores from the cetuximab-treated cohort.
ARTICLE ABSTRACTPurpose: To assess the prognostic value of epidermal growth factor receptor (EGFR) molecular characteristics of head and neck squamous cell carcinoma (HNSCC).Patients and Methods: HNSCC tumors from patients prospectively enrolled in either an Early Detection Research Network (EDRN) study and treated with surgery without an EGFR-targeted agent (N = 154) or enrolled in a chemoradiation trial involving the EGFR-targeted antibody cetuximab (N = 39) were evaluated for EGFR gene amplification by FISH and EGFR protein by immunohistochemical staining. Fresh-frozen tumors (EDRN) were also evaluated for EGFR protein and site-specific phosphorylation at Y992 and Y1068 using reverse-phase protein array (n = 67). Tumor (n = 50) EGFR and EGFRvIII mRNA levels were quantified using real-time PCR.Results: EGFR expression by immunohistochemistry (IHC) was significantly higher in the EDRN tumors with EGFR gene amplification (P < 0.001), and a similar trend was noted in the cetuximab-treated cohort. In the EDRN and cetuximab-treated cohorts elevated EGFR by IHC was associated with reduced survival (P = 0.019 and P = 0.06, respectively). Elevated expression of total EGFR and EGFR PY1068 were independently significantly associated with reduced progression-free survival in the EDRN cohort [HR = 2.75; 95% confidence interval (CI) = 1.26–6.00 and HR = 3.29; 95% CI = 1.34–8.14, respectively].Conclusions: In two independent HNSCC cohorts treated with or without cetuximab, tumor EGFR levels were indicative of survival. Tumor EGFR PY1068 levels provided prognostic information independent of total EGFR. Clin Cancer Res; 18(8); 2278–89. ©2012 AACR.