# TP53 mutation and del(17p)

Source: https://onco.cc/biomarkers/tp53-del17p/  
OnCo record `tp53-del17p` (Biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

TP53 mutation, or deletion of the 17p arm that carries the gene, is the single most common change in cancer and carries a worse outlook almost everywhere. In chronic lymphocytic leukaemia it decides treatment: chemotherapy is avoided and venetoclax's first approval was for del(17p) disease.

## Summary

TP53 status is read by sequencing (mutations in exons 4 to 10) and del(17p) by FISH; in endometrial and other cancers p53 immunohistochemistry (overexpression or complete absence) is the surrogate. Venetoclax (Venclexta) was first approved in 2016 for CLL with 17p deletion as detected by an FDA-approved test, the Vysis CLL FISH Probe Kit being the companion diagnostic; its CLL indications have since broadened to all patients, and guidelines (iwCLL, NCCN) keep TP53 status as the reason to prefer targeted agents over chemoimmunotherapy. In AML and MDS, TP53 mutation defines an adverse-risk group in ELN 2022 and the WHO and ICC 2022 classifications; in endometrial cancer p53-abnormal is one of the four molecular classes.

## Fields

- Kind: Biomarker
- Last checked: 2026-09-23
- Also known as: TP53 mutation; TP53-mutated; del(17p); 17p deletion; 17p-; TP53 aberration; p53 abnormal; TP53 disruption; TP53mut
- Tags: biomarker; tp53

## Notes

- Lymphoma: in mantle cell lymphoma this is the single result that most changes the plan, even though no label depends on it. Among 183 younger patients treated on the Nordic MCL2 and MCL3 protocols, TP53 mutation was present in 11% and TP53 deletion in 16%; only mutation kept its weight in multivariable analysis, with a hazard ratio of 6.2 for overall survival, median overall survival of 1.8 years against 12.7 years, and half of the mutated group relapsing within a year, with worse responses to both induction and high-dose chemotherapy (Eskelund 2017). In Richter transformation of chronic lymphocytic leukaemia, TP53 disruption was present in 47.1% of 86 cases and was the main prognostic variable (Rossi 2011). Mutation and deletion are not interchangeable: an immunohistochemical p53 stain approximates missense mutation and misses truncating ones, and FISH for del(17p) misses mutation without deletion, so sequencing is the complete test.

## Sources

- Venclexta prescribing information (DailyMed): https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=b118a40d-6b56-cee3-10f6-ded821a97018
- FDA: List of FDA-Authorized Companion Diagnostic Devices: https://www.fda.gov/medical-devices/in-vitro-diagnostics/list-cleared-or-approved-companion-diagnostic-devices-in-vitro-and-imaging-tools
- Eskelund et al., Blood 2017: TP53 mutations in 183 younger mantle cell lymphoma patients from Nordic MCL2 and MCL3: https://doi.org/10.1182/blood-2017-04-779736
- Rossi et al., Blood 2011: the genetics of Richter syndrome in 86 pathologically proven cases: https://doi.org/10.1182/blood-2010-09-302174

## Connected records

- biomarkers: [dMMR (mismatch repair deficiency by IHC)](https://onco.cc/biomarkers/dmmr-ihc/), [IDH1 R132 mutation](https://onco.cc/biomarkers/idh1-r132/), [MYCN amplification](https://onco.cc/biomarkers/mycn-amp/)
- terms: [del(17p) / TP53 aberration in CLL](https://onco.cc/terms/del17p-tp53/), [FISH / ISH (in situ hybridisation)](https://onco.cc/terms/fish/), [Li-Fraumeni syndrome (germline TP53)](https://onco.cc/terms/li-fraumeni/), [t(11;14), cyclin D1 and SOX11](https://onco.cc/terms/cyclin-d1-t11-14/), [TP53-mutated (p53-abnormal)](https://onco.cc/terms/tp53-mutated/)
- cancers: [Acute myeloid leukaemia](https://onco.cc/cancers/aml/), [Chronic lymphocytic leukaemia](https://onco.cc/cancers/cll/), [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Mantle cell lymphoma](https://onco.cc/cancers/mantle-cell-lymphoma/), [Myelodysplastic syndromes / neoplasms (MDS)](https://onco.cc/cancers/mds/), [Non-Hodgkin lymphoma (all types)](https://onco.cc/cancers/non-hodgkin-lymphoma/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [p53-abnormal endometrial cancer, including uterine serous carcinoma](https://onco.cc/cancers/endometrial-p53-abnormal/), [Relapsed or refractory chronic lymphocytic leukaemia](https://onco.cc/cancers/cll-relapsed/), [Richter transformation of chronic lymphocytic leukaemia](https://onco.cc/cancers/richter-transformation-cll/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- drugs: [Venetoclax](https://onco.cc/drugs/venetoclax/)
- targets: [TP53](https://onco.cc/targets/tp53/)

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