Table 2.

Performance of BRCA IHC by mechanism of loss

	BRCA1 loss (germline only)		BRCA1 loss (germline/somatic/methylation)
	No	Yes	No	Yes
BRCA1 IHC results
Normal	83	4	83	4
Abnormal	23	25	5	35
	Rate	95% CI	Rate	95% CI
BRCA1 IHC performance
Sensitivity	86.2%	73.7% to 98.8%	89.7%	80.2% to 99.3%
Specificity	78.3	70.5% to 86.2%	94.3%	89.5% to 99.2%
PPV	52.1%	38.0% to 66.2%	87.5%	77.3% to 97.8%
NPV	95.4%	91.0% to 99.8%	95.4%	91.0% to 99.8%
OCCR	80.0%	73.3% to 86.8%	92.9%	88.5% to 97.4%

PPV, positive predictive value; NPV, negative predictive value; OCCR, overall correct classification rate.