The primary quality management areas include:
- Validation: Proof of initial validation in which positive and negative HER2 categories are highly concordant (typically 95%). Laboratories performing these tests should ensure initial validation of 20 positive and 20 negative results for FDA-approved assays. While there is no specific concordance requirement for validation results, laboratories are responsible for ensuring the accuracy and reliability of test results by compliance with accreditation and proficiency testing requirements for HER2 assays.
- Controls: All controls should be reviewed. A pathologist or designee must document the review of external and internal controls for each test and each batch of tests.
- Proficiency testing: Regulatory agencies such as the College of American Pathologists (CAP) require that laboratories participate in and complete an external proficiency testing program that includes at least two annual testing events. Satisfactory performance (90% correct responses) is required on graded challenges. The laboratory must respond to its guiding regulatory agency if this is not met. HER2 testing may be suspended.
- Competency assessment: All pathologists testing and interpreting results should be assessed continuously. Any actions taken should be documented and retained in the laboratory record.
- Ongoing concordance measurements: Concordance between IHC and ISH assays should be 95%. However, the laboratory director's responsibility is to define the level of concordance in their laboratory and monitor it to provide accurate testing.
