Test Catalog

Test Id : KI67B

Ki-67(MIB-1), Breast, Quantitative Immunohistochemistry, Automated

Useful For
Suggests clinical disorders or settings where the test may be helpful

Determining proliferation of tumor cells in paraffin-embedded tissue blocks from patients diagnosed with breast carcinoma

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
KIBM Ki67 Breast IHC Manual No No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Cases that are not able to be scanned for automated analysis will be changed to the manual process for analysis.

Method Name
A short description of the method used to perform the test

Immunohistochemistry, Automated Quantitation

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Ki67 Breast IHC Automated

Lists additional common names for a test, as an aid in searching

Automated, Quantitative MIB-1








Ki-67 Breast IHC stain, RST

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Cases that are not able to be scanned for automated analysis will be changed to the manual process for analysis.

Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

Ki-67 immunohistochemistry testing on intracystic papillary carcinoma and solid papillary carcinoma, without clearly stating invasive carcinoma, is not appropriate and will be canceled without processing.


If ordering for diagnostic purposes, order PATHC / Pathology Consultation and request the stain.

Shipping Instructions

Attach the green pathology address label included in the kit to the outside of the transport container.

Necessary Information

1. Pathologist's name, address, and phone number are required.

2. Include accompanying pathology report stating the final diagnosis. If not available, a preliminary diagnosis is acceptable only if it refers to invasive or metastatic breast carcinoma.


Question ID Description Answers
MA023 Tumor type Primary breast carcinoma
Metastatic breast carcinoma
MA024 Tumor classification Metastatic breast carcinoma
Invasive breast carcinoma
Micro-invasive breast carcinoma

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Pathology Packaging Kit (T554)

Specimen Type: Preferred: Formalin-fixed, paraffin-embedded tissue block containing invasive or metastatic breast carcinoma

Acceptable: 2 Unstained sections, containing invasive or metastatic breast carcinoma, on charged slides cut at 4 microns less than 1 month ago. Tissue on the slides should have been fixed in 10% neutral buffered formalin. Also send one hematoxylin and eosin-stained slide if possible.

Submission Container/Tube: Pathology Packaging Kit

Collection Instructions: Submit paraffin-embedded invasive or metastatic breast carcinoma tissue.

Additional Information: Paraffin block will be returned with the final report.


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Oncology Test Request (T729)

-Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763)

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

No specimen should be rejected.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Special Ambient (preferred)

Useful For
Suggests clinical disorders or settings where the test may be helpful

Determining proliferation of tumor cells in paraffin-embedded tissue blocks from patients diagnosed with breast carcinoma

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Cases that are not able to be scanned for automated analysis will be changed to the manual process for analysis.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Ki-67 (MIB-1 clone) is a monoclonal antibody that reacts with cells undergoing DNA synthesis by binding to the Ki-67 antigen, a marker known to be expressed only in proliferating cells. By measuring the amount of tumor cells expressing Ki-67, an estimate of DNA synthesis can be determined. Studies suggest that Ki-67 (MIB-1) analysis of paraffin-embedded tissue specimens may provide useful prognostic and predictive information in various tumor types.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Varies by tumor type; values reported from 0% to 100%

Provides information to assist in interpretation of the test results

Results will be reported as a percentage of tumor cells staining positive for Ki-67 (MIB-1). Quantitative Ki-67 (MIB-1) results should be interpreted within the clinical context for which the test was ordered.


The scoring method using Aiforia artificial intelligence for image analysis was developed and validated in the Biomarker and Image Analysis Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic (see Method Description).

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The paraffin block analyzed must be representative of the patient's tumor.


Test results should be interpreted in the context of clinical findings and other laboratory data.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Urruticoechea A, Smith IE, Dowsett M: Proliferation marker Ki-67 in early breast cancer. J Clin Oncol 2005 Oct 1;23(28):7212-7220

2. de Azambuja E, Cardoso F, de Castro G, et al: Ki-67 as prognostic marker in early breast cancer: a meta-analysis of published studies involving 12,155 patients. Br J Cancer 2007 May 21;96(10):1504-1513

3. Nielsen TO, Leung SCY, Rimm DL, et al: Assessment of Ki67 in breast cancer: updated recommendations from the International Ki67 in Breast Cancer Working Group. J Natl Cancer Inst. 2021 Jul 1;113(7):808-819. doi: 10.1093/jnci/djaa201

4. Zhang A, Wang X, Fan C, et al: The role of Ki67 in evaluating neoadjuvant endocrine therapy of hormone receptor-positive breast cancer. Front. Endocrinol. 2021 Nov 3;12:687244

5. Polewski MD, Nielsen GB, Gu Y, et al: A standardized investigational Ki-67 immunohistochemistry assay used to assess high-risk early breast cancer patients in the monarchE Phase3 Clinical Study identifies a population with greater risk of disease recurrence when treated with endocrine therapy alone. Appl Immunohistochem Mol Morphol. 2022 Apr 1;30(4):237-245. doi: 10.1097/PAI.0000000000001009

Method Description
Describes how the test is performed and provides a method-specific reference

A 4 micron-thick section is cut from the paraffin block. The section is stained with an immunoperoxidase method using the monoclonal antibody Ki-67 (MIB-1 clone). This is the paraffin nuclear epitope to the Ki-67 antigen. Any nucleus that has an antigen-antibody complex will cause the bright-field, brown chromogen, diaminobenzidine (DAB), to precipitate onto it. All nuclei, both DAB positive and negative, are counterstained with diluted hematoxylin.


Ki-67 (MIB-1)-stained slides are scanned using the Leica Aperio GT450 digital scanner. The captured digital image is analyzed in Aiforia by an artificial intelligence algorithm. The Aiforia software renders a percentage of positive-staining tumor nuclei. A technologist reviews the analyzed digital image and ensures at least 80% of the total invasive or metastatic cancer is analyzed appropriately. The Aiforia data and corresponding slide are reviewed by a pathologist for final interpretation.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

4 to 6 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week after results are reported. Material made at Mayo Clinic may be retained at Mayo Clinic indefinitely.

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
KI67B Ki67 Breast IHC Automated 85330-9
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
MA023 Tumor type 44638-5
MA024 Tumor classification 21918-8
70995 Interpretation 85330-9
70996 Participated in the Interpretation No LOINC Needed
70997 Report electronically signed by 19139-5
70999 Material Received 81178-6
71627 Disclaimer 62364-5
71841 Case Number 80398-1

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports