The diagnostic power of immunohistochemical scoring methods for predicting L858R and E746-A750 deletion by EGFR mutation-specific antibodies.

ROC = receiver operating characteristic, CI = confidence interval, PPV = positive predictive value, NPV = negative predictive value, LR+ = positive likelihood ratio, LR- = negative likelihood ratio.The optimal cut-off point was defined as the one with the least (1 - sensitivity)2 + (1 - specificity)2.*Logistic regression model to evaluate the predicted probability of the interaction between the two IHC scoring system.