# Field cancerisation

Source: https://onco.cc/pathways/field-cancerisation/  
OnCo record `field-cancerisation` (Pathway). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cancer often arises from a whole region of tissue that already carries mutations, not from one rogue cell. Sun-exposed skin, smokers' airways, and Barrett's oesophagus are patchworks of mutant clones competing long before a tumour appears.

## Summary

Deep sequencing of normal tissue shows that by middle age, sun-exposed skin, oesophagus (NOTCH1, TP53), bronchial epithelium, endometrium, and colon crypts are colonised by clones carrying cancer-driver mutations, most of which never progress. Field effects explain second primary tumours and local recurrence after resection, and they define who benefits from interception (chemoprevention, surveillance). Clonal competition can even be protective (NOTCH1-mutant oesophageal clones outcompete TP53 clones). Understanding the transition from field to tumour is the central question for early detection and prevention.

## Fields

- Kind: Pathway
- Last checked: 2026-09-08
- Tags: mechanism
- Analogy: A lawn where many patches have already turned to weeds. Any single tumour is one patch that took over; mowing it leaves the rest of the lawn ready to sprout again.
- Interventions: Surveillance and ablation of precancer (Barrett's RFA, cervical precancer ablation, colon polypectomy); Chemoprevention (aspirin in Lynch, tamoxifen, HPV vaccination); Field-directed therapy after resection (e.g., 5-FU cream for actinic keratosis); Molecular monitoring of fields (cytosponge, sputum, urine)

## Notes

- Leading programmes: Jones (Wellcome Sanger) on clones in normal oesophagus and skin; Campbell/Stratton (Sanger) on somatic mutation in normal tissues; Fitzgerald (Cambridge/CRUK) on Barrett's interception; Hopkins on field cancerisation in head and neck.
- Sun-damaged skin is the clearest field in medicine, and it is why skin cancer is hard to count. A person with one keratinocyte cancer usually has a field of damaged skin that will produce more, which is why treatment is often aimed at an area rather than a spot, and why a registry rule that records only the first tumour per person misses most of the disease (see `keratinocyte-cancer-counting`).

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Field_cancerization
- Martincorena et al., Somatic mutant clones colonize the human esophagus with age (Science 2018): https://doi.org/10.1126/science.aau3879

## Connected records

- terms: [Actinic keratosis (solar keratosis): sun damage, not cancer](https://onco.cc/terms/actinic-keratosis/), [Ageing tissue and clonal fields: cancer as a disease of old tissue](https://onco.cc/terms/ageing-tissue-field-theory/), [Barrett's oesophagus](https://onco.cc/terms/barretts-esophagus/), [Cervical precancer (CIN, HSIL/LSIL)](https://onco.cc/terms/cin-hsil/), [Clonal evolution and the ecological view of cancer](https://onco.cc/terms/clonal-evolution-theory/), [Creams, light and cold for basal cell carcinoma](https://onco.cc/terms/topical-and-destructive-treatment-bcc/), [In situ](https://onco.cc/terms/in-situ/), [Inherited syndromes that cause skin cancer: Gorlin syndrome and xeroderma pigmentosum](https://onco.cc/terms/inherited-skin-cancer-syndromes/), [Keratinocyte cancer (and why 'non-melanoma skin cancer' is being retired)](https://onco.cc/terms/keratinocyte-cancer/), [Skin cancer after an organ transplant](https://onco.cc/terms/skin-cancer-after-organ-transplant/), [Skin cancer after cancer treatment](https://onco.cc/terms/second-primary-skin-cancer-after-cancer-treatment/), [The next skin cancer: second primaries after a keratinocyte cancer](https://onco.cc/terms/second-primary-skin-cancer/), [What is not a second cancer: recurrence, metastasis and field cancerisation](https://onco.cc/terms/rejuv-second-what-is-not-a-second-cancer/), [Why nobody knows how many skin cancers there are: the counting rule behind every figure](https://onco.cc/terms/keratinocyte-cancer-counting/)
- cancers: [Basal cell carcinoma](https://onco.cc/cancers/basal-cell-carcinoma/), [Bowen's disease (squamous cell carcinoma in situ)](https://onco.cc/cancers/bowens-disease/), [Cervical cancer](https://onco.cc/cancers/cervical/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Cutaneous squamous cell carcinoma](https://onco.cc/cancers/cutaneous-scc/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Oesophageal cancer](https://onco.cc/cancers/esophageal/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)
- technologies: [Chemoprevention & risk-reducing surgery](https://onco.cc/technologies/chemoprevention/), [Endoscopic resection (EMR / ESD)](https://onco.cc/technologies/endoscopic-resection/), [HPV & HBV vaccination](https://onco.cc/technologies/hpv-vaccine/), [Thermal ablation and cryotherapy for cervical precancer](https://onco.cc/technologies/precancer-ablation/)
- targets: [NOTCH1](https://onco.cc/targets/notch1/), [TP53](https://onco.cc/targets/tp53/)
- institutions: [Cancer Research UK](https://onco.cc/institutions/cruk/), [Johns Hopkins Hospital / Sidney Kimmel Comprehensive Cancer Center](https://onco.cc/institutions/johns-hopkins/), [The Francis Crick Institute](https://onco.cc/institutions/francis-crick/)
- pathways: [Basement membrane & tissue barriers](https://onco.cc/pathways/basement-membrane-tissue-barriers/), [Clonal evolution & minimal residual disease](https://onco.cc/pathways/clonal-evolution/), [Epigenetic reprogramming](https://onco.cc/pathways/epigenetic-reprogramming/), [Theories of cancer: how the ideas connect](https://onco.cc/pathways/theories-of-cancer/)
- key papers: [Genomic and evolutionary classification of lung cancer in never smokers](https://onco.cc/key-papers/paper-zhang-lung-cancer-never-smokers-nat-genet-2021/), [Martincorena: normal sun-exposed skin is a patchwork of cancer-mutation clones](https://onco.cc/key-papers/paper-martincorena-somatic-mutations-normal-skin-science-2015/), [Somatic mutant clones colonize the human esophagus with age](https://onco.cc/key-papers/paper-martincorena-science/), [The landscape of somatic mutation in normal colorectal epithelial cells](https://onco.cc/key-papers/paper-lee-six-somatic-mutation-normal-colorectal-crypts-nature-2019/)
- trials: [TUMORAPA (switching from a calcineurin inhibitor to sirolimus after a transplant skin cancer)](https://onco.cc/trials/tumorapa/)
- ideas: [Intercept cancer at the field stage](https://onco.cc/ideas/idea-field-interception/)

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JSON: https://onco.cc/api/v1/entities/field-cancerisation.json