Test Catalog

Test ID: FGF1F    
FGFR1 (8p11.2) Amplification, FISH, Tissue

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

Providing prognostic information and guiding treatment primarily for patients with squamous cell carcinoma of the lung, breast, esophagus, thymus, and other locations

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 consult. 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

Fibroblast growth factor receptor 1 (FGFR1) is a receptor tyrosine kinase.  FGFR1 overexpression or amplification in squamous cell carcinoma is associated with tumor growth. Studies have shown overexpression or amplification of FGFR1 to be vulnerable to FGFR-tyrosine kinase inhibitors and FGFR1 inhibitors maybe a promising therapeutic option and have shown tumors with FGFR1 amplification may be sensitive to FGFR1 tyrosine kinase inhibitors.

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

FGFR1 will be clinically interpreted as positive or negative.


The FGFR1 locus is reported as amplified when the FGFR1:D8Z2 ratio is >2.0 or an average of 6 or more copies of the FGFR1 locus are observed per tumor nucleus.


A tumor with an FGFR1:D8Z2 ratio < or =2.0 and having an average of <6 copies of FGFR1 per tumor nucleus is considered negative for amplification of the FGFR1 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 US Food and Drug Administration and is best used as an adjunct to existing clinical and pathologic information.


Fixatives other than formalin (eg, Prefer, Bouin) 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 40 paraffin-embedded tissue samples from patients with various tumors. A series of normal control samples were used to generate the normal cutoffs. FGFR1 amplification was detected in 2 of 40 (5%) of samples. Other abnormalities including aneusomy, duplication and deletion of FGFR1 were also identified and may be observed in addition to FGFR1 amplification in tumor samples.

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

1. Schultheis AM, Bos M, Schmitz K, et al: Fibroblast growth factor receptor 1 (FGFR1) amplification is a potential therapeutic target in small-cell lung cancer. Mod Pathol 2014 Feb;27(2):214-212

2. Heist RS, Mino-Kenudson M, Sequist LV, et al: FGFR1 amplification in squamous cell carcinoma of the lung. J Thorac Oncol 2012 Dec;7(12):1775-1780

3. Weis J, Sos ML, Seidel D, et al: Frequent and focal FGFR1 amplification associates with therapeutically tractable FGFR1 dependency in squamous cell lung cancer. Sci Transl Med 2010 Dec 15;2(62):62ra93

4. Craddock KJ, Ludkovski O, Sykes J, et al: Prognostic value of fibroblast growth factor receptor 1 gene locus amplification in resected lung squamous cell carcinoma. J Thorac Oncol 2013 Nov;8(11):1371-1377

5. Schildhaus HU, Heukamp LC, Merkelbach-Bruse S, et al: Definition of a fluorescence in-situ hybridization score identifies high- and low-level FGFR1 amplification types in squamous cell lung cancer. Mod Pathol 2012 Nov;25(11):1473-1480