ATM and MRE11 protein expression levels in the TC were tested in a forward and reverse binary logistic regression analysis using a data set of immunohistochemical scoring derived from 257 tumor samples and 255 normal tissues. The final biomarker model gave an average receiver operator characteristic area under the curve (ROC-AUC) value of 0.849 for the combination of the two proteins. Similarly, ATM and MRE11 protein expression levels in the TP (tumor, n = 258; normal, n = 255) were also tested, and the model gave an average ROC-AUC value of 0.837. The sensitivity and specificity of the two-protein combined panel were 80.9% and 70.3% for TC and 61.6% and 48.8% for TP, respectively, and overall accuracy was 75.6% (TC) and 55.2% (TP) (S1 Table).