Testing for HER2: Sensitivity Versus Specificity

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Testing for HER2: Sensitivity Versus Specificity

Before placing a patient on Herceptin®, it is critical to perform accurate testing in order to achieve a favorable outcome for the patient. No test exists that is both 100% sensitive and specific. Sensitivity and specificity are further explained below:
  • Sensitivity - Measures the proportion of TRUE POSITIVES that are correctly identified. The sensitivity of a HER2 test reflects the patients identified as HER2-positive who WILL benefit from a specific therapy. A test with 100% sensitivity would identify ALL the HER2-positive patients tested (no false-negatives).
  • Specificity - Measures the proportion of TRUE NEGATIVES that are correctly identified. The specificity of a HER2 test reflects the patients identified as HER2-negative who would NOT benefit from a specific therapy. A test with 100% specificity would identify ALL the HER2-negative patients tested (no false-positives).