Background:
The FGFR1 FISH tests are designed to detect amplification (FGFR1/CEP8) or translocation (FGFR1 break-apart) of the FGFR1 (fibroblast growth factor receptor 1) locus at chromosome 8p11.2. FGFRs have roles in development, cell proliferation and differentiation and angiogenesis. Overexpression of FGFR1 by translocation or gene amplification has been reported across an array of cancer and tumor types, including breast cancer, lung cancer and leukemia, and has generally been associated with poor prognosis. Recent studies suggest that the FGFR pathway may be susceptible to FGFR inhibitors, thus having potential promise for pharmacologic intervention (Liang et al. 2012 Trends Pharmacol Sci 33).
FISH studies are useful adjuncts to complete chromosome studies, particularly when following an abnormal clone, assessing relapse and progression, or when material is inadequate for chromosomal analysis.
- FGFR1/CEP8 probe set, to detect FGFR1 amplification.
(Cutoff for amplification: ≥2.2 ratio of FGFR1:CEP8)
- FGFR1 break-apart probe set, to detect FGFR1 disruption.
Methodology:
FISH is performed on sections of formalin-fixed, paraffin-embedded tumor tissue. Slides are prepared per standard protocols and 100 interphase cells are scored. For other specimen types (bone marrow, blood), 200 interphase cells are scored.
Specimen Requirements:
- Formalin-fixed paraffin-embedded tumor block or FFPE slides:
- If sending slides, please include H&E stained slide cut from same block
- Preferred slice thickness is 4-5 microns on positively charged slides.
- Please submit 3-5 slides. Store at room temperature.
- Contact Client Services at (855) 535-1522 for shipping supplies and instructions.
- Bone Marrow: Shortly before aspiration add 0.2 cc of Sodium Heparin (1,000 units/ml) to tube of transport medium (please contact lab to arrange for transport medium to be sent). Add at least 1 cc of bone marrow aspirate to the tube and suspend well. Allow no clots to form.
- Peripheral blood: May be used if bone marrow is inaspirable and blasts (.5%) are present. 3-5 mL drawn into a GREEN top sodium heparin vacutainer tube or into a pre-heparinized plastic syringe (use 0.2 cc sodium heparin, 1000 unit/mL). Do NOT use lithium heparin.
- Bone core biopsy: May also provide cells in cases where marrow is severely packed. Send in transport medium with Sodium Heparin.
*Sterile Ringer’s solution, either lactated or non-lactated and sterile isotonic saline are alternatives, if no complete RPMI is available. Contact Client Services for more information on media requirements.
It is preferable to collect the specimen before initiation of chemotherapy in the patient. Tumor samples should be selected from viable areas, with as little normal or necrotic material as possible.
Unacceptable specimens are acellular, necrotic specimens, septic specimens, specimens in fixative or frozen, or specimens collected more than one week previously.
Keep at room temperature and transport to laboratory as soon as possible.
Contact Client Services at (855) 535-1522 for supplies and instructions.
A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please include detailed clinical information, including clinical history.
Test Performed (Days):
Mon - Sat
Turn Around Time:
3 - 7 days
Shipment Sensitivity Requirements:
Ship via overnight express, using the FedEx priority overnight label provided. Use cold pack to keep the specimens cool, but not frozen.
Contact Client Services at (855) 535-1522 for shipping kits and instructions.
References:
Additional Info:
1. Liang et al. 2012 Trends Pharmacol Sci 33