Test Id : PTENC
PTEN (SP218), Semi-Quantitative Immunohistochemistry, Manual
Useful For
Suggests clinical disorders or settings where the test may be helpful
Aiding in detecting PTEN-deficient invasive prostate adenocarcinoma
Method Name
A short description of the method used to perform the test
Immunohistochemistry (IHC)
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
Aliases
Lists additional common names for a test, as an aid in searching
Phosphate and Tensin Homolog
SP218
Specimen Type
Describes the specimen type validated for testing
Special
Shipping Instructions
Attach the green "Attention Pathology" address label (T498) to the outside of the transport container before putting into the courier mailer.
Necessary Information
A pathology/diagnostic report and a brief history are required.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Specimen Type: Tissue
Supplies: Pathology Packaging Kit (T554)
Submit:
Formalin-fixed, paraffin-embedded tissue block
OR
3 Unstained glass, "positively charged" slides with 4-microns formalin-fixed, paraffin-embedded tissue
Additional Information: One slide will be stained with hematoxylin and eosin and returned.
Forms
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Decalcified paraffin embedded tissue | Reject |
| Wet/frozen tissue | Reject |
| Cytology smears | Reject |
| Noncharged slides | Reject |
| ProbeOn slides | Reject |
| Snowcoat slides | Reject |
| Nonformalin fixed tissue, including CytoLyt, SurePath, alcohol-formalin-acetic acid (AFA), 95% ethanol, PREFER and zinc formalin fixatives | Reject |
| Nonparaffin embedded tissue | Reject |
| Broken or cracked unstained slides | Reject |
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) | ||
| Refrigerated | |||
Useful For
Suggests clinical disorders or settings where the test may be helpful
Aiding in detecting PTEN-deficient invasive prostate adenocarcinoma
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The PTEN (SP218) RxDx Assay is indicated as a companion diagnostic to detect and select PTEN-deficient invasive prostate carcinoma patients who may potentially benefit from a combination treatment with capivasertib (TRUQAP).
Clinical cutoff for PTEN loss is greater than or equal to 90% of viable malignant cells with no specific cytoplasmic expression.
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.
An interpretive report will be provided.
Interpretation
Provides information to assist in interpretation of the test results
The PTEN protein is localized in the cytoplasm and nucleus, and is an essential enzyme expressed in several non-neoplastic tissues. The PTEN (SP218) RxDx Assay is indicated as a companion diagnostic to aid in identifying patients who may be eligible for treatment with TRUQAP (capivasertib). Clinical cutoff for PTEN loss is greater than or equal to 90% of viable malignant cells with no specific cytoplasmic expression. Nuclear expression in viable malignant cells should be disregarded.(1)
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test has been validated for non-decalcified paraffin-embedded tissue specimens fixed in 10% neutral buffered formalin at Mayo Clinic in Rochester, Minnesota. Specimens are recommended to be placed in formalin within 1 hour of acquisition and fixed between 6 hours and 72 hours. This assay has not been validated on tissue or cellblocks subjected to alternative fixatives or decalcification.
Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.
The charge of glass slides can be affected by environmental factors and subsequently may alter slide staining. Sending unsuitable glass slides can result in inconsistent staining due to poor slide surface chemistry.
Best practices for storage of positively charged slides:
-Minimize time slides are stored after being unpackaged
-Limit exposure to high humidity and heat
-Minimize exposure to plastics
Broken or cracked unstained slides are not compatible with the instrumentation used in our performing laboratories and will be rejected. Additional material may be requested.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Ventana PTEN (SP218) RxDx Assay Data Sheet. Roche Diagnostics; 1019742US, 02/01/2026
2. Jamaspishvili T, Berman DM, Ross AE, et al. Clinical implications of PTEN loss in prostate cancer. Nat Rev Urol. 2018;15(4):222-234
3. Shah RB, Shore KT, Yoon J, Mendrinos S, McKenney JK, Tian W. PTEN loss in prostatic adenocarcinoma correlates with specific adverse histologic features (intraductal carcinoma, cribriform gleason pattern 4 and stromogenic carcinoma). Prostate. 2019;79(11):1267-1273
4. Fizazi K, Clarke NW, De Santis M, et al. Capivasertib plus abiraterone in PTEN-deficient metastatic hormone-sensitive prostate cancer: CAPItello-281 phase III study. Ann Oncol. 2026;37(1):53-68. doi:10.1016/j.annonc.2025.10.004
Method Description
Describes how the test is performed and provides a method-specific reference
Immunohistochemical staining and detection of PTEN (SP218) is performed in formalin-fixed, paraffin-embedded tissue sections using the VENTANA PTEN (SP218) RxDx Assay. The 4-micron tissue sections are deparaffinized, subjected to heat-induced antigen retrieval and peroxidase inhibitor, incubated with a rabbit monoclonal antibody (SP218), and visualized using a proprietary kit detection system. Sections are counterstained with hematoxylin and post counterstained with bluing. Stained slides are examined microscopically by the consulting anatomic pathologist.(Package insert: VENTANA PTEN [SP218] RxDx Assay. Ventana Medical Systems, Inc; 1019742US, 02/01/2026)
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.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees
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 has been modified from the manufacturer's instructions. Its performance characteristics were 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.
CPT codes are provided by the performing laboratory.
88360
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 |
|---|---|---|
| PTENC | PTEN (SP218), SemiQuant IHC, Manual | 81706-4 |
| 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.
|
|---|---|---|
| 624278 | Interpretation | 59465-5 |
| 624287 | Participated in the Interpretation | No LOINC Needed |
| 624288 | Report electronically signed by | 19139-5 |
| 624289 | Material Received | 81178-6 |
| 624290 | Disclaimer | 62364-5 |
| 624291 | Case Number | 80398-1 |