Figure 7. Correlation of ALDH1A2 protein expression and clinical outcome of OPSCC patients.
(A) Representative images at different power of ALDH1A2 expression on tissue microarrays of normal mucosa and exemplary tumors with low and high protein levels (brown signal). Counterstaining with hematoxylin. Scale bars: 100 μm. (B) Lower ALDH1A2 expression score in non–HPV-driven (n = 89) versus HPV-driven (n = 26) tumors. Bars denote medians. *P < 0.05, 2-tailed Mann-Whitney U test. Kaplan-Meier plots for OS (C) and PFS (D) with regard to ALDH1A2 protein levels in n = 115 OPSCC patients. P values were derived by log-rank/Mantel-Cox test.