49683-6
LaboratoryERBB2 gene copy number/Chromosome 17 copy number in Tissue by FISH
Definition
The ratio of HER-2/neu (ERBB2 gene) to CEP17 probes by in situ hybridization assays (e.g. FISH) to determine overexpression of HER-2/neu protein in breast cancer. CEP17 is used as an internal control and to account for aneusomy (varying number) of chromosome 17. A ratio of >2.0 indicates gene amplification and overexpression of HER-2/neu according to the 2013 ASCO-CAP HER2 test guideline recommendations. Results are used to assist in dose selection for certain drugs, assess eligibility for trastuzumab (Herceptin®) treatment, predict response to drug therapies and overall survival in patients with breast cancer. For testing without an internal control probe, see LOINCs 31150-6 and 48675-3. For determining HER-2 status by Immunohistochemistry (IHC), see LOINC 18474-7.
LOINC 6-Axis Classification
Component
ERBB2 gene copy number/Chromosome 17 copy number
Property
NRto
Time Aspect
Pt
System
Tiss
Scale Type
Qn
Method Type
FISH
Details
Class
MOLPATH
Order/Observation
Both
Short Name
ERBB2 copy num/Chr 17 copy num Tiss FISH
Display Name
ERBB2 copy number/Chromosome 17 copy number FISH (Tiss) [# ratio]
Related Names
Frequently Asked Questions
What is LOINC code 49683-6?
LOINC code 49683-6 identifies "ERBB2 gene copy number/Chromosome 17 copy number in Tissue by FISH". The ratio of HER-2/neu (ERBB2 gene) to CEP17 probes by in situ hybridization assays (e.g. FISH) to determine overexpression of HER-2/neu protein in breast cancer. CEP17 is used as an internal control and to account for aneusomy (varying number) of chromosome 17. A ratio of >2.0 indicates gene amplification and overexpression of HER-2/neu according to the 2013 ASCO-CAP HER2 test guideline recommendations. Results are used to assist in dose selection for certain drugs, assess eligibility for trastuzumab (Herceptin®) treatment, predict response to drug therapies and overall survival in patients with breast cancer. For testing without an internal control probe, see LOINCs 31150-6 and 48675-3. For determining HER-2 status by Immunohistochemistry (IHC), see LOINC 18474-7.
What does 49683-6 measure?
This code measures ERBB2 gene copy number/Chromosome 17 copy number in Tiss. It belongs to the MOLPATH class in the LOINC classification.
What is LOINC?
LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.