Gene expression profile of peripheral blood in colorectal cancer

Table 6 Performance of the statistical model on the training, testing sets and external validation dataset from 12 public microarray studies with Logit(P) = 0.5

	Training set	Testing set	External validation
Non-Cancers	107	120	88
True negative	98	110	72
False positive	9	10	16
Colorectal Cancers	55	56	519
False negative	12	19	15
True positive	43	37	504
Total	162	176	607
Sensitivity	78.2%	66.1%	97.1%
Specificity	91.5%	91.7%	81.8%
PPV	82.7%	78.7%	96.9%
NPV	89.1%	85.3%	82.8%
Accuracy	87.0%	83.5%	94.9%

Logit(P): Logistic probabilities; PPV: Positive predictive value; NPV: Negative predictive value.