HER2, Breast, Quantitative Immunohistochemistry, Automated
Method Description Describes how the test is performed and provides a method-specific reference
Testing is performed using FDA-approved Ventana Pathway HER2 (4B5) rabbit monoclonal primary antibody and a proprietary detection system.(Package insert: PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody)
No expression (HER2 score of 0), low expression (HER2 score of 1+) and high expression (HER2 score of 3+) controls are used. HER2 immunohistochemical (IHC) slides are scanned using the Aperio ScanScope instrument, which captures digital images of the patient slide. The technologist views the digitized image on a computer monitor and using a tracing tool available in ImageScope (Aperio Technologies Inc), traces around areas of invasive cancer capturing no less than 75% of the total cancer within the image. The traced areas are then analyzed using a laboratory-developed image analysis algorithm designed to maximize concordance with HER2 fluorescence in situ hybridization. All analyzed cells are identified as having either a HER2 staining intensity of 0, 1+, 2+, or 3+. A case will be called 3+ if 30% or more of the cells fall into the 3+ category, which is in accordance with CAP/ASCO guidelines. Cases will be called 2+ if more than 10% of the cells are stained at the 2+ level, 1+ if more than 10% are stained at the 1+ level, and 0 if less than 10% of the cells are stained at the 1+ or higher levels. In cases with less than 30% of cells staining at the 3+ level, the highest score (2+, 1+, or 0) that has at least 10% of cells staining at that level will be the final score. The slides and test results are then reviewed by a pathologist who provides a final interpretation.(Wolff AC, Hammond ME, Schwartz JN, et al: American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. Arch Pathol Lab Med 2007;131:18-43)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Until 1 week after results are reported
Performing Laboratory Location The location of the laboratory that performs the test