# Gene amplification and copy-number change

Source: https://onco.cc/terms/gene-amplification/  
OnCo record `gene-amplification` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cancer cells often have extra copies of a growth gene (amplification) or have lost copies of a protective one (deletion), rather than a spelling change within the gene. Extra copies of HER2 or MYCN are classic examples that change treatment.

## Summary

Amplification (detected by FISH, ISH or NGS copy-number calls) drives overexpression: HER2 in breast and gastric cancer, MYCN in high-risk neuroblastoma, MET amplification as a resistance route to EGFR inhibitors, CCNE1 in ovarian and gastric cancer, MDM2 in liposarcoma, CDK4 in glioma. Deletions remove tumour suppressors: del(17p)/TP53 in CLL and myeloma (predicting chemo-resistance), CDKN2A/B in glioma (defining grade 4), MTAP (creating a PRMT5 vulnerability), 9p21 loss linked to immunotherapy resistance. Loss of heterozygosity and large-scale copy changes are summed into genomic-scar scores used to infer HRD and predict PARP inhibitor benefit.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: amplification; amplified; amplifications; copy number; copy-number; copy number alteration; copy number gain; gene copy number; MYCN-amplified; MET amplification; CCNE1 amplification; deletion; homozygous deletion; del(17p); 1q gain; loss of heterozygosity; LOH; genomic instability; chromosomal instability; aneuploidy

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Gene_duplication
- Wikipedia: https://en.wikipedia.org/wiki/Gene_duplication

## Connected records

- terms: [Cytogenetics and karyotype](https://onco.cc/terms/cytogenetics/), [FISH / ISH (in situ hybridisation)](https://onco.cc/terms/fish/), [HER2 testing in biliary tract cancer (IHC, ISH and NGS)](https://onco.cc/terms/her2-testing-in-biliary-cancer/), [HER2-positive (IHC 3+ or ISH-amplified)](https://onco.cc/terms/her2-positive/), [Homologous recombination deficiency (HRD)](https://onco.cc/terms/hrd/)
- fronts: [Diagnostics & Biomarkers](https://onco.cc/fronts/diagnostics/)
- technologies: [Comprehensive genomic profiling](https://onco.cc/technologies/cgp/), [Histopathology & immunohistochemistry](https://onco.cc/technologies/histopathology-ihc/)
- targets: [FGFR1](https://onco.cc/targets/fgfr1/), [HER2](https://onco.cc/targets/her2/), [MDM2](https://onco.cc/targets/mdm2/), [MYCN (N-myc)](https://onco.cc/targets/mycn/), [PRMT5 (MTAP-deleted cancers)](https://onco.cc/targets/prmt5-mtap/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Gallbladder cancer](https://onco.cc/cancers/gallbladder/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- key papers: [A molecularly annotated platform of patient-derived xenografts identifies HER2 as an effective therapeutic target in cetuximab-resistant colorectal cancer](https://onco.cc/key-papers/paper-bertotti-xenopatients-her2-cetuximab-resistant-colorectal-cancer-discov-2011/), [Assessment of a HER2 scoring system for colorectal cancer: results from a validation study](https://onco.cc/key-papers/paper-valtorta-her2-scoring-colorectal-heracles-mod-pathol-2015/), [Circulating tumor DNA-guided treatment with pertuzumab plus trastuzumab for HER2-amplified metastatic colorectal cancer: a phase 2 trial (TRIUMPH)](https://onco.cc/key-papers/paper-nakamura-triumph-ctdna-pertuzumab-trastuzumab-her2-colorectal-nat-med-2021/), [Comprehensive genomic characterization of squamous cell lung cancers](https://onco.cc/key-papers/paper-tcga-lung-squamous-nature-2012/), [Frequent and focal FGFR1 amplification associates with therapeutically tractable FGFR1 dependency in squamous cell lung cancer](https://onco.cc/key-papers/paper-weiss-fgfr1-amplification-squamous-lung-sci-transl-med-2010/), [Genomic hallmarks and structural variation in metastatic prostate cancer](https://onco.cc/key-papers/paper-quigley-structural-variation-mcrpc-cell-2018/), [In vivo amplification of the androgen receptor gene and progression of human prostate cancer](https://onco.cc/key-papers/paper-visakorpi-androgen-receptor-amplification-nat-genet-1995/), [MET amplification leads to gefitinib resistance in lung cancer by activating ERBB3 signaling](https://onco.cc/key-papers/paper-engelman-met-amplification-gefitinib-resistance-science-2007/), [MET exon 14 mutations in non-small-cell lung cancer are associated with advanced age and stage-dependent MET genomic amplification and c-Met overexpression](https://onco.cc/key-papers/paper-awad-met-exon-14-mutations-lung-jco-2016/), [Molecular characterisation of neuroendocrine prostate cancer and identification of new drug targets](https://onco.cc/key-papers/paper-beltran-nepc-aurka-mycn-cancer-discov-2011/), [Trastuzumab deruxtecan in patients with HER2-positive advanced colorectal cancer (DESTINY-CRC02): primary results from a multicentre, randomised, phase 2 trial](https://onco.cc/key-papers/paper-destiny-crc02-lancet-oncol-2024/), [Tucatinib plus trastuzumab for chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer (MOUNTAINEER)](https://onco.cc/key-papers/paper-strickler-mountaineer-tucatinib-trastuzumab-lancet-oncol-2023/)
- biomarkers: [9p24.1 alteration of the PD-1 ligand loci](https://onco.cc/biomarkers/pd-ligand-9p24-alteration/), [AR amplification (gene and upstream enhancer)](https://onco.cc/biomarkers/ar-amplification/), [HER2 ISH amplified (ERBB2 gene amplification)](https://onco.cc/biomarkers/her2-ish-amplified/), [MET amplification (gene copy number)](https://onco.cc/biomarkers/met-amplification-readout/), [MYCN amplification](https://onco.cc/biomarkers/mycn-amp/), [Nectin-4 expression](https://onco.cc/biomarkers/nectin-4-expression/)

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