LOINC Code 49683-6: ERBB2 copy number/Chromosome 17 copy number FISH (Tiss) [# ratio]

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component ERBB2 gene copy number/Chromosome 17 copy number. It is commonly used with the system or sample type Tiss.

When is it used?

• Used in lab systems, EHRs, and clinical data exchange.
• May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
• Status: ACTIVE
• Order vs observation: Both
• Method: FISH

What it does not mean

• The code identifies the observation or test, not the actual result.

Key facts

• ERBB2 gene copy number/Chromosome 17 copy number in Tissue by FISH
• ERBB2 gene copy number/Chromosome 17 copy number
• 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.
• breast cancer; CD340; CEP17; c-erb B2; Chr 17 copy num; Chromosom; Chromosome 17 centromere; Chromosome Enumeration Probe 17; Chromosomes; ErbB-2; ERBB2 copy num; erb-b2 receptor tyrosine kinase 2; Fluorescent in situ hybridization; Genetics; HER2; HER-2; HER2/neu; HER-2/neu; Heredity; Heritable; Inherited; MLN 19; Molecular pathology; MOLPATH; NEU; NGL; No; Num; Number ratio; Oncology; p185; Point in time; QNT; Quan; Quant; Quantitative; Random; Tissue; Tissue, unspecified; TKR1; v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (neuro/glioblastoma derived oncogene homolog)

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Frequently asked questions