Table IV.

Summary of the diagnostic value of antibodies for a panel of eight TAAs in breast cancer.

Serum	Any TAA positive	All TAA negative	Total
BC	25 (A)	16 (C)	41 (R1)
NHS	9 (B)	73 (D)	82 (R2)
Total	34 (C1)	89 (C2)	123 (N)

Fourfold table χ² tests: χ²=34.164, P=0.000. Sensitivity (%) = A/(A + C) = 25/41 = 61.0%. Specificity (%) = D/(B + D) = 73/82 = 89.0%. Youden’s index = Sensitivity + Specificity − 1 = 0.610 + 0.890 − 1 = 0.500. Positive (+) likelihood ratio = Sensitivity/(1 − Specificity) = 0.610/(1 − 0.890) = 5.545. Negative (-) likelihood ratio = (1 − Sensitivity)/Specificity = (1 − 0.610)/0.890 = 0.438. Percentage agreement = (A + D)/(A + B + C + D) × 100 = (25 + 73)/(25 + 16 + 9 +73) × 100 = 79.7%. κ = [N(A + D) − (R₁C₁ + R₂C₂)]/[N² − (R₁C₁ + R₂C₂)] = 0.52. TAA, tumor-associated antigen; BC, breast cancer; NHS, normal human sera.