HER2 Immunohistochemistry: Workflow Experience with Image Analysis Based Interpretation of CB11 and

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HER2 Immunohistochemistry Workflow Experience
with Image Analysis Based Interpretation of CB11
and 4B5 Clones

• Jeffrey Fine MD, Rohit Bhargava MD, Urvashi
  Surthi PhD, and David Dabbs MD
• Magee-Womens Hospital of UPMC

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Disclaimer

• One of the abstract authors (David Dabbs) is a
  consultant for Ventana
• None of the other authors have any conflicts of
  interest to report

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Objectives

• Overview of Her2/NEU testing (IHC)
• Recap of validation results
• Discuss implementation of image analysis

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Her2/NEU

• Test for responsiveness to Trastuzumab
  (Herceptin)
• Trastuzumab is cardiotoxic and is very expensive
• False positives are highly undesirable
• Trastuzumab can increase survival or reduce risk
  of recurrence
• False negatives are also undesirable

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CAP HER2-A Survey (Spring 2007)

• 40 TMA cores (4 slides)
• Stained/interpreted at institutions (350ish)
• Consensus (gt80) in 22 of 40 cases
• Very variable

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IHC Variables

• Pre-analytic
• Fixation issues, tissue processing
• Analytic
• Validation, Calibration, Antibody clone, Antigen
  retrieval, Automation, Controls, etc.
• Post-analytic
• Interpretation criteria
• QA procedures
• Image analysis (17.9 reported using it)

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Validation of IA at UPMC

• Formalin fixed (8-48 hours) paraffin embedded
  tissue
• Automated IHC platform (Ventana)
• CB11 and 4B5 antibodies (Ventana)
• VIAS (Ventana Image Analysis System)
• FISH (Vysis)

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VIAS (image from vendor)
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Validation Results I

• System differentiated between tumor and stroma
  (subjective impression)
• Pathologist had to find invasive tumor (and
  exclude in-situ tumor)

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Classification (Tumor vs. Stroma)
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Results CB11

• 100 Concordance with FISH (n52)
• 0/1 IHC with no amp by FISH
• 3 with amp by FISH
• FISH rate (2 rate)
• Expert 22.9 (n118)
• VIAS 21.2
• (expert was also 100 concordant)

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Results 4B5

• 94.6 Concordance with FISH (n56)
• 100 Concordance with new reference range
• FISH rate (2)
• Expert 21.9 (n114)
• VIAS 28.9 (n117)
• new reference range

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Reference Range

• VIAS assigns a raw number score to each case
  which is then rounded to the nearest whole
  number.
• Out of the boxscore 2.5 or higher was rounded to
  3
• New range is conservativeonly cases with score
  3.5 are called 3

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Demixed to show brown
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Old Workflow
Mailbox
Office
Order Her2/NEU
Retrieve IHC Stain
Interpret Stain
Dictate Results
Sign out case
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New Workflow
Office
Mailbox
IA Workstation
Order Her2/NEU
Retrieve IHC Stain
Perform IA
Dictate Results
Sign out case
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Implementation Details

• Billing
• Fee code 88361
• Technical charge initiated by order in APLIS
• Documentation
• VIAS results printout retained with other case
  paperwork (requisition)
• IHC results (ER/PR and Her2/NEU) dictated into
  canned text that includes VIAS blurb

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Documentation Support

• Transcription
• New quick text with VIAS sentence
• Communication with Transcription Team
• Slide/paper management personnel
• Communication do not discard results report
• Back-up of data
• Currently performed manually

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Consumables

• IA charged per click
• IHC Laboratory responsible for keeping an
  adequate supply of the click reagent
• Smart Card (100 tests)

Image from nist.gov www site
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Training

• Local Domain Expert (me)
• Fellows
• Selected Faculty
• Other Faculty
• Residents

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Status Report

• IA is in production for a week
• Bumps being ironed out
• Transcription
• Training
• End experience varies

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Good

• Should increase standardization
• Recent switch to 4B5 clone different appearance
  and possible differences in interpretation
• Documented response to pressure for accurate
  Her2/NEU testing
• Foot in the door for other IA applications
• Vendor has been responsive and appears to want to
  improve shortcomings

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Bad

• IA of new antibody is less accurate than that of
  discontinued antibody
• Reference range work-around
• Workflow involves travel and is more labor
  intensive than traditional method
• Quality improvement but does not extend the
  pathologist
• Operator error is possible
• Data entry
• Lighting
• Focusing

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Future IA (More Automation)

• Whole Slide Images (some systems do permit IA)
• Slide could be scanned in the IHC lab, and
  results (with the electronic slide) delivered
  straight to the pathologist
• Automated detection of invasive tumor
• Transition of IA to non-pathologist staff
• Electronic interfaces to support test ordering
  and resulting (no more paper print outs or
  dictation)

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Conclusions

• IA is validated and should improve performance of
  Her2/NEU IHC testing by reducing post-analytic
  variability
• Current IA set-up not ideal but an important
  first step
• Successful implementation in a busy academic
  setting
• Revenue (digital pathology business case)