Test Catalog

Test ID: PROF    
Prostate Tumor, FISH, Tissue

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

Identifying PTEN gene deletion or rearrangements in patients with prostatic adenocarcinoma

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

This test does not include a pathology consultation. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge. This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results.


Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

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

The tumor suppressor gene PTEN is often altered in patients with prostate cancer. Patients with advanced tumors have a deletion of the PTEN gene locus. Rearrangement or separation may be another mechanism responsible for inactivation of the PTEN gene. FISH analysis allows for the detection of deletion, homozygous deletion, and rearrangement of the PTEN gene region.

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

A positive result with the PTEN probe is detected when the percent of cells with an abnormality exceeds the normal cutoff for the probe set. A positive result of PTEN suggests inactivating structural alterations of the PTEN gene region at 10q23. A negative result suggests no structural alterations of the locus.

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

This test is not approved by the FDA and is best used as an adjunct to existing clinical and pathologic information.


Fixatives other than formalin (eg, Prefer, Bouin's) may not be successful for FISH assays, however nonformalin fixed samples will not be rejected.


Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Supportive Data

FISH analysis was performed on 65 formalin-fixed paraffin-embedded specimens including 25 prostatic adenocarcinoma tissue samples, 15 prostatic adenocarcinoma needle biopsy and 25 noncancerous control specimens. The normal controls were used to generate the normal cutoff values. Structural alterations resulting in the inactivation of the PTEN were identified and results correlated with pathology and immunohistochemical findings.

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

1. Krohn A, Diedler T, Burkhardt L, et al: Genomic deletion of PTEN is associated with tumor progression and early PSA recurrence in ERG fusion-positive and fusion-negative prostate cancer. Am J Pathol 2012;181(2):401-412

2. Gao T, Mei Y, Sun H, et al: The association of Phosphatase and tensin homolog (PTEN) deletion and prostate cancer risk: A meta-analysis. Biomed Pharmacother 2016;83:114-121

3. Lotan TL, Carvalho FL, Peskoe SB, et al: PTEN loss is associated with upgrading of prostate cancer from biopsy to radical prostatectomy. Mod Pathol 2015;28:128-137