Table 2.

Ability of Moderate-to-Strong EGFR Expression to Predict EGFR Amplification in Diffusely Infiltrative Gliomas

Diagnostic parameter	All gliomas	Non-GBM gliomas	GBM only
Sensitivity	1.0 (0.98–1.0)	1.0 (0.85–1.0)	1.0 (0.98–1.0)
Specificity	0.39 (0.34–0.44)	0.37 (0.30–0.44)	0.27 (0.21–0.32)
PPV	0.59 (0.54–0.62)	0.14 (0.088–0.20)	0.52 (0.47–0.57)
NPV	0.99 (0.97–1.0)	1.0 (0.96–1.0)	0.99 (0.93–1.0)

The 95% CIs are given in parentheses. Moderate-to-strong EGFR IHC immunoreactivity (see Figure 1) is extremely sensitive and has a uniformly high NPV, but its specificity and PPV vary whether the focus is on all gliomas, non-GBM gliomas, or GBM only.

NPV, negative predictive value; PPV, positive predictive value.