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. Documentation of review of external and internal controls for each test and each batch of tests is required and should be reviewed by a pathologist or designee.
- Proficiency testing: Regulatory agencies such as the College of American Pathologists (CAP) require that laboratories participate in and successfully complete an external proficiency testing program in which at least two testing events occur per year. Satisfactory performance (90% correct responses) are required on graded challenges. In the event this is not met, the laboratory will be required to respond to their guiding regulatory agency. HER2 testing may be suspended.
- Competency assessment: Ongoing competency should be assessed for all pathologists involved in testing and interpretation of results. Any actions taken should be documented and retained as part of the laboratory record.
- Ongoing concordance measurements: Concordance between IHC and ISH assays should be 95%, but it is the responsibility of the laboratory director of each laboratory to define the level of concordance in his/her laboratory and monitor it in order to provide accurate testing.
