Expression of EGFR, VEGF, and NOTCH1 suggest differences in tumor angiogenesis in HPV-positive and HPV-negative head and neck squamous cell carcinoma

Abstract

There is current interest in anti-angiogenesis therapies for head and neck squamous cell carcinomas (HNSCC), although the utility of these therapies in human papillomavirus (HPV) positive and HPV-negative HNSCC is unclear. Therefore, we explored heterogeneity in expression of a distal factor in angiogenesis (EGFR, the epidermal growth factor receptor), a proximal factor in angiogenesis (VEGF, the vascular endothelial growth factor) and a putative factor in angiogenesis (NOTCH1) in a HNSCC case series using immunohistochemistry in N = 67 cases (27 HPV-positive, 40 HPV-negative, by in situ hybridization). Box plots and the Wilcoxon rank sum or Kruskal-Wallis tests were used to compare staining scores (intensity × percent of cells staining) by HPV status and lifestyle factors. Associations between EGFR, VEGF, and NOTCH1 were assessed using box plots and Spearman correlation (ρ) in all cases, and stratified by HPV status. HPV-negative HNSCC over-expressed EGFR [median (range): 30 (0-300)] relative to HPV-positive HNSCC [7.5 (0-200)] (P = 0.006). VEGF and NOTCH1 were unrelated to HPV status (P > 0.05). EGFR was associated with VEGF in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive HNSCC (ρ = 0.25, P = 0.20). NOTCH1 and VEGF were associated in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive tumors (ρ = -0.12, P = 0.57). NOTCH1 was not associated with EGFR (P > 0.05). Our results are suggestive of heterogeneity in HNSCC angiogenesis. Future studies should explore angiogenesis mechanisms in HPV-positive and HPV-negative HNSCC.

Fig. 1

a Low EGFR expression (×200). b High EGFR expression (×200). c Positive control for EGFR (head and neck cancer) (×200). d Low VEGF expression (×200). e High VEGF expression (×200). f Positive control for VEGF (normal kidney) (×200). g Low NOTCH1 expression (×200). h High NOTCH1 expression (×200). i Positive control for NOTCH1 (lung cancer)

Fig. 2

Expression of EGFR by tertile of VEGF expression a all tumors, b HPV-positive tumors, c HPV-negative tumors. P value is from Kruskal–Wallis test

Fig. 3

Expression of NOTCH1 by tertile of VEGF expression a all tumors, b HPV-positive tumors, c HPV-negative tumors. P value is from Kruskal–Wallis test