Survey of Immunohistochemistry (IHC) Validation Practice

Form Approved
OMB No. 0920-XXXX
Exp. Date xx/xx/20xx

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Online:

cap.org (preferred method)

Fax:

866-FAX-2CAP (866-329-2227)

Public reporting burden of this collection of information varies from 15 to 30 minutes with
an estimated average of 20 minutes per response, including the time for reviewing
instructions, searching existing data sources, gathering and maintaining the data needed, and
completing and reviewing the collection of information. An agency may not conduct or
sponsor, and a person is not required to respond to a collection of information unless it
displays a currently valid OMB control number. Send comments regarding this burden
estimate or any other aspect of this collection of information, including suggestions for
reducing this burden to CDC/ATSDR Information Collection Review Office, 1600 Clifton
Road NE, MS D-74, Atlanta, Georgia 30333; ATTN: PRA (0920-XXXX).

Survey of Immunohistochemistry (IHC) Validation
Practices and Procedures
The College of American Pathologists (CAP) Pathology Laboratory Quality Center: Cooperative Agreement with Centers for Disease Control and Prevention (CDC)
Post Survey from CAP Proficiency Testing Mailing HER2B-2010 and "Principles of Analytic Validation of Immunohistochemical Assays" Evidence-Based Guideline
2014

Introduction
The CAP is collaborating with the CDC on a cooperative agreement, "Improving the Impact of Laboratory Practice Guidelines: A New Paradigm
for Metrics." We invite your laboratory to assist our goal of examining the current state of IHC validation practices and procedures by completing
this important follow-up survey to the original one sent in the 2010 HER2-B mailing. Your participation is completely voluntary and we appreciate
your time which is estimated to take 20 minutes for completion. We recommend that you have your current laboratory procedures available. Your
responses will remain anonymous. All information collected in this survey will be kept in a secure manner. No individual answers will be shared
with the CDC. Your CAP number will connect your survey answers to demographic data on file and will ensure that only one response per
laboratory is received. The CAP and the CDC will publish the post-survey overall results as part of the cooperative agreement. If you have any
questions, please email center@cap.org.
Validation of nonwaived test systems is mandated by Clinical Laboratory Improvement Amendments of 1988 (CLIA 88). Since the introduction of
immunohistochemistry, this test has been used as an adjunct to morphologic diagnosis and has not been subject to rigorous quality control and
quality assurance measures.
Recently, with the introduction of prognostic and therapeutic Food and Drug Administration (FDA)-approved IHC tests (eg, HER2) and the 2013
publication, "Principles of Analytic Validation of IHC Assays,"1 the field is being provided with more precise and consistent test procedures in
validation.
Please note that this survey does not apply to HER2 or the ER and PgR assays as separate guidelines for those markers have already been
established. A list of terms and definitions are included below:
TERM

DEFINITION

Analytic Validity

A test's ability to accurately measure the analyte of interest.

Clinical Validity

A test's ability to detect or predict a disorder, a prognostic risk, or likelihood of treatment response.

Predictive Marker

A stand-alone test that provides information on likely response to a given therapy and may directly determine
therapy (eg, CD20, CD117).

Non-Predictive Marker

A test usually done as part of a panel and interpreted only in the context of other morphologic and clinical data.

Laboratory developed test
(LDT)

A test developed within a clinical laboratory that is performed by the laboratory in which the test was developed
and is neither FDA-cleared nor approved.

Laboratory modified test
(LMT)

An FDA-cleared or approved test that is modified by a clinical laboratory.
Modified means any change to the assay that could affect its performance specifications for sensitivity,
specificity, accuracy, or precision, etc. Such modifications include but are not limited to:
Changes in specimen handling;
Changes in incubation times or temperatures;
Changes in specimen or reagent dilution;
Change in antibody;
Change or elimination of a procedural step;
Change in antigen detection system;
Change in scoring for semi-quantitative assays.

Validation

A defined process by which a laboratory confirms that a laboratory-developed or modified test performs as
intended or claimed.

Verification

The process by which a laboratory determines that a FDA-cleared or approved assay performs according to the
recommendations set forth by the manufacturer.

1 Fitzgibbons

PL, Bradley LA, Fatheree LA, et al. Principles of analytic validation of immunohistochemical assays: Guideline from the College of American Pathologists
Pathology and Laboratory Quality Center. Arch Pathol Lab Med. 2014;138(11):1432-1443.

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN1

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section I: IHC Validation Procedures
The following questions pertain to all IHC assays other than HER2, ER and PgR.
1.

Does your laboratory perform IHC staining?
010

2.

Does your laboratory have separate written procedures for validation of IHC predictive and non-predictive markers?
020

3.

129 Yes
130 No
503 Unsure

Does your laboratory have a written procedure that outlines the steps needed for analytic validation of new IHC assays?
030

4.

129 Yes
130 No, we only do interpretation (STOP HERE. Thank you for your response.)

657

Yes, for predictive markers only (other than HER2, ER, and PgR)

658

Yes, for non-predictive markers only

659

Yes, for both predictive and non-predictive markers

130

No (Skip to question 10.)

503

Unsure (Skip to question 10.)

Does the written procedure include specification for verifying unmodified FDA-approved assays?
040

129 Yes
130 No
259
503

5.

Does the written procedure include specification for validation of LDT or LMT assays?
050

6.

Not applicable; we don’t have FDA-approved or cleared IHC assays
Unsure

660
661

Yes, for predictive LDTs or LMTs only (other than HER2, ER and PgR)
Yes, for non-predictive LDTs or LMTs only

662
130

Yes, for both predictive and non-predictive LDTs or LMTs
No

259

Not applicable; we do not create LDTs or LMTs

503

Unsure

Does the written procedure include any specifications for validating IHC tests performed on cytologic specimens
(eg, alcohol fixed cell blocks, smears, cytospins)?
060

657

Yes, for predictive markers only

658
659

Yes, for non-predictive markers only
Yes, for both predictive and non-predictive markers

130
259

No
Not applicable; we do not perform IHC tests on cytology specimens

503

Unsure

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN2

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section I: IHC Validation Procedures, cont'd
7.

Does the written procedure include any specifications for validating IHC tests performed on decalcified specimens?
010

657
658
659
130
259
503

Yes, for predictive markers only
Yes, for non-predictive markers only
Yes, for both predictive and non-predictive markers
No
Not applicable; we do not perform IHC tests on decalcifed specimens
Unsure

Section II: Documentation Procedures
8.

Please answer the following in regards to validation of new IHC antibody assays in your laboratory.
If your laboratory does not have separate procedures, please complete Table A only.
Table A
When validating a new non-FDA approved, non-predictive IHC assay (eg, cytokeratin, S100, CD45), does your laboratory…
OR complete if there is only one procedure in your laboratory for both non-predictive and predictive IHC assays.
Yes
020

No

129

Test a specified minimum number of cases?

030

130

663

130

663

130

663

130

663

.

Total number:
040

Unsure/Not applicable

129
050

Include specified numbers of positive and negative
cases in the validation set?

.

Positive number:
060

.

Negative number:
070

129

080

Require minimum positive and negative concordance
rates?

Positive rate:

.

%

.

%

090

Negative rate:
100

Require a minimum overall concordance rate?

129

110

Overall rate:

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

.

%

APN3

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section II: Documentation Procedures, cont'd
8.

Continued from previous page.
Table B
When validating a new non-FDA approved predictive marker
IHC assay other than HER2, ER/PgR (eg, CD20), does your laboratory…
Yes
010

No

129

Test a specified minimum number of cases?

020

130

663

130

663

130

663

130

663

.

Total number:
030

Unsure/Not applicable

129
040

Include specified numbers of positive and negative
cases in the validation set?

.

Positive number:
050

.

Negative number:
060

129

070

Require minimum positive and negative concordance
rates?

Positive rate:

.

%

.

%

080

Negative rate:
090

Require a minimum overall concordance rate?

100

Overall rate:

9.

129

.

%

Does your laboratory document validations and verifications of IHC assays?
110

664

Yes, always

665

Yes, sometimes

130

No

503

Unsure

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN4

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section III: Re-Validation Procedures
10. For an existing validated IHC assay, does your laboratory have a written procedure that specifies when to reassess
an assay when there are changes in the conditions of testing to ensure it performs as expected?
010

657
658
659

Yes, for predictive markers only (other than HER2, ER and PgR)
Yes, for non-predictive markers only
Yes, for both predictive and non-predictive markers

130
503

No (Skip to question 12.)
Unsure (Skip to question 12.)

11. Please answer the following in regards to re-validation of existing IHC antibody assays in your laboratory.
If your laboratory does not have separate procedures, please complete Table A only.
Table A
Are the following changes explicitly specified when re-validating non-FDA approved, non-predictive IHC assays (eg, cytokeratin, S100, CD45)?
OR complete if there is only one procedure in your laboratory for non-predictive and predictive assays.
*If yes, please provide case information.

Yes*

No

Unsure

No.** of cases
specified

No.** of cases
variable and set by
Laboratory Director

No.** of cases
not specified

030

Introduction of a new lot of antibody

020

129

130

503

Change in antibody dilution

050

129

130

503

Change in antibody vendor (same clone)

080

129

130

503

Change in antibody clone

110

129

130

503

Introduction or change in antigen
retrieval method

140

129

130

503

Change in incubation or retrieval times
(same method)

170

129

130

503

Change in antigen detection system

200

129

130

503

Change in fixative type

230

129

130

503

Change in tissue processing equipment

260

129

130

503

Change in testing equipment

290

129

130

503

Change in environmental conditions
(eg, laboratory relocation)

320

129

130

503

Change in water supply

350

129

130

503

.

040

666

667

.

070

666

667

.

100

666

667

.

130

666

667

.

160

666

667

.

190

666

667

.

220

666

667

.

250

666

667

.

280

666

667

.

310

666

667

.

340

666

667

.

370

666

667

060

090

120

150

180

210

240

270

300

330

360

**No. of cases refers to typical minimum number cases required to test in validation set.

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN5

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section III: Re-Validation Procedures, cont'd
11. Continued from previous page.
Table B
Are the following changes explicitly specified when re-validating non-FDA approved predictive marker IHC assays
other than HER2, ER/PgR (eg, CD20)?
*If yes, please provide case information.

Yes*

No

Unsure

No.** of cases
specified

No.** of cases
variable and set by
Laboratory Director

No.** of cases
not specified

020

Introduction of a new lot of antibody

010

129

130

503

Change in antibody dilution

040

129

130

503

Change in antibody vendor (same clone)

070

129

130

503

Change in antibody clone

100

129

130

503

Introduction or change in antigen
retrieval method

130

129

130

503

160

129

130

503

Change in antigen detection system

190

129

130

503

Change in fixative type

220

129

130

503

Change in tissue processing equipment

250

129

130

503

Change in testing equipment

280

129

130

503

Change in environmental conditions
(eg, laboratory relocation)

310

129

130

503

Change in water supply

340

129

130

503

.

030

666

667

050

.

060

666

667

.

090

666

667

.

120

666

667

.

150

666

667

.

180

666

667

.

210

666

667

.

240

666

667

.

270

666

667

.

300

666

667

.

330

666

667

.

360

666

667

080

110

Change in incubation or retrieval times
(same method)

140

170

200

230

260

290

320

350

**No. of cases refers to typical minimum number cases required to test in validation set.

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN6

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section IV: General IHC Laboratory Data
Please answer the following questions with respect to ALL IHC assays currently in use.
12. What is the total number of antibodies in use in your IHC laboratory?
010

.
13. What was the total number of new antibodies introduced into your laboratory during 2014?
020

.
14. What was the total number of surgical pathology accessions in your laboratory during 2014?
030

.
15. Please provide the following information on the most recent IHC assay that your laboratory newly placed into
clinical service.
040

.

Year introduced

050

503 Unsure

070

503 Unsure

060

Name of antibody

Was a validation study performed for this
antibody assay?

080

129 Yes

130 No

503 Unsure

*If yes, please provide the following information.
090

Total number of cases included in the
validation set

.

100

503 Unsure

.

120

503 Unsure

140

503 Unsure

160

503 Unsure

.

180

503 Unsure

.

200

503 Unsure

110

Number of known positives cases tested
130

.

Positive concordance rate
150

.

Number of known negative cases tested

170

Negative concordance rate

190

Overall concordance rate

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN7

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section IV: General IHC Laboratory Data, cont'd
16. For your most recent IHC antibody assay, what primary method of validation did your laboratory use?
010

668

Correlated the new test’s results with the morphology and expected results

669

Compared the new test's results with the results of prior testing of the same tissues with
a validated assay in the same laboratory

670

Compared the new test's results with the results of testing the same tissue validation set
in another laboratory using a validated assay

671

Compared the new test’s results with previously validated non-immunohistochemical tests

672

Tested previously graded tissue challenges from a formal proficiency testing program
(if available) and compared the results with the graded responses

010

Other, specify:

020

503 Unsure

Section V: Awareness and Adoption
17. Prior to this survey, were you aware and/or familiar with the CAP "Principles of Analytic Validation of IHC Assays" 1
guideline published in 2014?
030

129 Yes
673 No, however plan to review the guideline within next 6 months (Skip to question 21.)
674

No, and do not plan to review the guideline (Skip to question 21.)

18. What is your current status with adopting the CAP "Principles of Analytic Validation of IHC Assays" 1 guideline
recommendations that apply to your laboratory practice?
040

675
676

Currently adopted all recommendations
Adopted some, but not all, recommendations

677
678

Plan to adopt all or some within the next 6 months
Plan to adopt all or some within the next 7-12 months

679

Do not plan to adopt unless they become requirement from accreditation agency

19. How do you currently use (or plan to use) the CAP "Principles of Analytic Validation of IHC Assays" 1 guideline
recommendations? (Fill all that apply.)
050

680

Prospectively for newly acquired antibodies for predictive markers

681
682

Prospectively for newly acquired antibodies for non-predictive markers
Prospectively for revalidation situations

683
684

Retrospectively to revalidate antibodies currently in use
Do not plan to use

1 Fitzgibbons

PL, Bradley LA, Fatheree LA, et al. Principles of analytic validation of immunohistochemical assays: Guideline from
the College of American Pathologists Pathology and Laboratory Quality Center. Arch Pathol Lab Med. 2014;138(11):1432-1443.

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN8

Results must be received at the CAP no later than
midnight, Central Time by the due date below:

Section V: Awareness and Adoption, cont'd
20. Please indicate the most difficult aspect(s) about adopting the guideline recommendations into your validation process.
(Choose up to three responses.)
010

685

Number of cases recommended for predictive assays

686

Number of cases recommended for non-predictive assays

687

Number of cases available for routine antigens

688

Number of cases available for rare antigens

689

Achieving 90% concordance

690

Incorporating high-low expressors

691

Assessing cytology specimens

692

Assessing decalcified specimens

100

693

Changes in testing conditions (revalidation requirements); specify:

694

Documentation

695

Sufficient time/staff to run validations

696

Additional cost/expense

010

Other, specify:

650

Not applicable; do not plan to use

150

Section VI: Additional Information
21. What is your primary role/job title?
170

697
698

IHC Laboratory Director – MD/DO
IHC Laboratory Director – PhD

699
700
701
702

IHC Laboratory Director – Other medical credential(s), specify:
Department Chair/Laboratory Medical Director
Staff pathologist
IHC section/Histotechnology Supervisor/Manager

703

180

Quality Assurance Manager
190

704

Other role/title, specify:

22. Please provide any other additional information or comments on IHC validation practices in your laboratory.
200

Thank you for responding to this 2015 IHC Validation Practices and Procedures Survey. Your laboratory may be invited to
participate in a focus group.

Customer Contact Center 800-323-4040 option 1 (domestic)
or 001-847-832-7000 option 1 (international)

APN9