# Basal cell carcinoma

Source: https://onco.cc/cancers/basal-cell-carcinoma/  
OnCo record `basal-cell-carcinoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Basal cell carcinoma is a skin cancer and the most common cancer of all, caused by sun exposure and almost never life-threatening. Nearly all are removed surgically; the rare advanced cases are treated with drugs that block the hedgehog signalling pathway, and with immunotherapy if those fail.

## Summary

Basal cell carcinoma arises from hedgehog-pathway activation in nearly every case, through loss of PTCH1 (~70%) or activating SMO mutations (~10-20%); germline PTCH1 loss causes Gorlin (basal cell nevus) syndrome. Subtypes range from indolent nodular and superficial to infiltrative, morphoeic and basosquamous tumours with higher recurrence risk.

Treatment is surgical (excision, Mohs for high-risk sites), with curettage, topical imiquimod or 5-fluorouracil, photodynamic therapy and radiotherapy as alternatives for low-risk or inoperable lesions. Vismodegib (ERIVANCE, 2012) and sonidegib (BOLT, 2015) are oral SMO inhibitors for locally advanced or metastatic BCC with ~45-60% response; their class toxicities (muscle spasms, dysgeusia, alopecia, weight loss) cause many to stop, and resistance arises through SMO mutations. Cemiplimab (2021) is approved after hedgehog-inhibitor failure or intolerance. Nicotinamide and sun protection reduce new BCCs in high-risk patients.

## Fields

- Kind: Cancer
- Last checked: 2026-09-08
- Also known as: BCC; Basal Cell Carcinoma of the Skin
- Tags: gap-fill; skin
- Group: skin
- Burden: The most common human cancer: several million cases per year in the US alone; metastasis is exceptionally rare (<0.1%), but locally advanced disease can be destructive.
- Subtypes: Nodular (most common); Superficial; Infiltrative / morphoeic (high-risk); Basosquamous; Gorlin syndrome (germline PTCH1/SUFU)
- Biomarkers: Histologic subtype and high-risk location (H-zone of face); PTCH1 / SMO / SUFU alterations (research; SMO mutations predict hedgehog-inhibitor resistance); Perineural invasion; Germline PTCH1 (Gorlin)

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/basal-cell-carcinoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/basal-cell-carcinoma/#overview [1 subtype, 4 state-of-the-art points]
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/basal-cell-carcinoma/#what-it-is [6 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/basal-cell-carcinoma/#finding-it [4 biomarkers, 1 prevalence rows]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/basal-cell-carcinoma/#treating-it [3 settings, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/basal-cell-carcinoma/#evidence [11 trials, 1 key paper, 6 milestones]
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/basal-cell-carcinoma/#science [33 targets, 1 pathway]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/basal-cell-carcinoma/where-you-are/ [2 centres]
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/basal-cell-carcinoma/#living-with-it [14 questions, 5 red cards]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/basal-cell-carcinoma/coming/ [8 medicines, 11 trials, 3 open problems]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/basal-cell-carcinoma/data/ [88 connected records]

## Standard of care

- Low-risk: Standard excision with 4 mm margin, curettage and electrodesiccation, or topical imiquimod / 5-FU / photodynamic therapy for superficial lesions. ([Fluorouracil (5-FU)](https://onco.cc/drugs/fluorouracil/))
- High-risk or recurrent: Mohs micrographic surgery or excision with complete margin assessment; radiotherapy if surgery not feasible. ([IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/))
- Locally advanced or metastatic: Vismodegib or sonidegib; cemiplimab after hedgehog-inhibitor failure or intolerance; multidisciplinary review for surgery/radiotherapy after response. ([Vismodegib](https://onco.cc/drugs/vismodegib/), [Sonidegib](https://onco.cc/drugs/sonidegib/), [Cemiplimab](https://onco.cc/drugs/cemiplimab/))

## State of the art

- Hedgehog inhibitors are among the few targeted drugs whose rationale came straight from a developmental-biology pathway and a hereditary syndrome (Gorlin).
- Cemiplimab gives a second line after hedgehog-inhibitor failure.
- Neoadjuvant vismodegib can shrink tumours to make surgery less destructive (VISMONEO).
- Chemoprevention (nicotinamide) reduces new keratinocyte cancers in high-risk patients.

## Open problems

- Hedgehog-inhibitor tolerability leads most patients to stop within a year.
- Resistance via SMO mutations has no approved next-in-class agent.
- Huge volume: dermatology and Mohs capacity, and cost of treating millions of low-risk lesions.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Basal-cell_carcinoma
- NCCN Guidelines: Basal Cell Skin Cancer: https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1416
- ERIVANCE (NEJM 2012): https://doi.org/10.1056/NEJMoa1113713
- NCI PDQ: skin cancer: https://www.cancer.gov/types/skin/patient/skin-treatment-pdq

## Connected records

- cancers: [Cutaneous squamous cell carcinoma](https://onco.cc/cancers/cutaneous-scc/), [Locally advanced and metastatic basal cell carcinoma](https://onco.cc/cancers/locally-advanced-bcc/), [Melanoma](https://onco.cc/cancers/melanoma/), [Merkel cell carcinoma](https://onco.cc/cancers/merkel-cell-carcinoma/), [SHH-activated medulloblastoma](https://onco.cc/cancers/medulloblastoma-shh/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)
- technologies: [Black salve and other escharotic pastes](https://onco.cc/technologies/black-salve-escharotics/), [Chemoprevention & risk-reducing surgery](https://onco.cc/technologies/chemoprevention/), [Confocal microscopy and optical coherence tomography for skin (VivaScope, VivoSight, deepLive)](https://onco.cc/technologies/confocal-oct-skin-imaging/), [Dermoscopy, total-body photography & AI skin analysis](https://onco.cc/technologies/dermoscopy-ai/), [Electrochemotherapy devices (Cliniporator)](https://onco.cc/technologies/electrochemotherapy-devices/), [Electron beam therapy systems (linac electrons, total skin electron units, mobile electron IORT)](https://onco.cc/technologies/electron-beam-therapy-systems/), [Hedgehog pathway inhibitors](https://onco.cc/technologies/hedgehog-inhibitors/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Photodynamic therapy lasers and light sources](https://onco.cc/technologies/photodynamic-therapy-lasers/), [Skin cancer screening (visual skin examination)](https://onco.cc/technologies/skin-cancer-screening/), [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/), [Superficial and orthovoltage radiotherapy for skin cancer](https://onco.cc/technologies/superficial-radiotherapy/)
- targets: [ARHGAP35](https://onco.cc/targets/arhgap35/), [ARHGEF10L](https://onco.cc/targets/arhgef10l/), [BACH2](https://onco.cc/targets/bach2/), [BNC2](https://onco.cc/targets/bnc2/), [CCDC6](https://onco.cc/targets/ccdc6/), [CPEB3](https://onco.cc/targets/cpeb3/), [CPVL](https://onco.cc/targets/cpvl/), [CTSS](https://onco.cc/targets/ctss/), [CYP1B1](https://onco.cc/targets/cyp1b1/), [KNL1](https://onco.cc/targets/knl1/), [KRT5](https://onco.cc/targets/krt5/), [LATS1](https://onco.cc/targets/lats1/), [LPP](https://onco.cc/targets/lpp/), [MC1R](https://onco.cc/targets/mc1r/), [MSN](https://onco.cc/targets/msn/), [NACA](https://onco.cc/targets/naca/), [OCA2](https://onco.cc/targets/oca2/), [PABPC1](https://onco.cc/targets/pabpc1/), [PD-1](https://onco.cc/targets/pd1/), [PPM1D](https://onco.cc/targets/ppm1d/), [PPP6C](https://onco.cc/targets/ppp6c/), [PTCH1 (Patched 1)](https://onco.cc/targets/ptch1/), [PTPN14](https://onco.cc/targets/ptpn14/), [RASA1](https://onco.cc/targets/rasa1/), [RNASET2](https://onco.cc/targets/rnaset2/), [SLC45A2](https://onco.cc/targets/slc45a2/), [Smoothened (hedgehog pathway)](https://onco.cc/targets/smoothened/), [TGM3](https://onco.cc/targets/tgm3/), [TNS3](https://onco.cc/targets/tns3/), [Toll-like receptor 7 (TLR7)](https://onco.cc/targets/tlr7/), [TYR](https://onco.cc/targets/tyr/), [XPA](https://onco.cc/targets/xpa/), [ZBTB10](https://onco.cc/targets/zbtb10/)
- drugs: [Aminolevulinic acid (topical, for photodynamic therapy)](https://onco.cc/drugs/aminolevulinic-acid/), [Cemiplimab](https://onco.cc/drugs/cemiplimab/), [Fluorouracil (5-FU)](https://onco.cc/drugs/fluorouracil/), [Imiquimod](https://onco.cc/drugs/imiquimod/), [Methyl aminolevulinate](https://onco.cc/drugs/methyl-aminolevulinate/), [Nicotinamide](https://onco.cc/drugs/nicotinamide/), [Sonidegib](https://onco.cc/drugs/sonidegib/), [Vismodegib](https://onco.cc/drugs/vismodegib/)
- companies: [Caliber Imaging and Diagnostics](https://onco.cc/companies/caliber-imaging-diagnostics/), [DAMAE Medical](https://onco.cc/companies/damae-medical/), [Galderma](https://onco.cc/companies/galderma/), [Michelson Diagnostics](https://onco.cc/companies/michelson-diagnostics/), [Philogen S.p.A.](https://onco.cc/companies/philogen-s-p-a/), [Regeneron](https://onco.cc/companies/regeneron/), [Roche / Genentech](https://onco.cc/companies/roche-genentech/), [Sanofi](https://onco.cc/companies/sanofi/)
- pathways: [Basal cell carcinoma (KEGG map)](https://onco.cc/pathways/basal-cell-carcinoma-signalling/)
- terms: [Cancer stem cell theory and phenotypic plasticity](https://onco.cc/terms/cancer-stem-cell-theory/), [Immune-related adverse events (irAEs)](https://onco.cc/terms/irae/)
- trials: [BOLT](https://onco.cc/trials/bolt/), [Clinical Trial to Evaluate BO-112 in Patients With Basal Cell Carcinoma (BCC)](https://onco.cc/trials/nct06422936/), [Efficacy and Safety of Patidegib Gel 2% for Preventing Basal Cell Carcinomas on the Face of Adults With Gorlin Syndrome](https://onco.cc/trials/nct06050122/), [ERIVANCE BCC](https://onco.cc/trials/erivance/), [Flash Radiotherapy for Skin Cancer](https://onco.cc/trials/nct07455331/), [L19IL2 or L19TNF or L19IL2/TNF in Patients With Basal Cell Carcinoma (BCC)](https://onco.cc/trials/nct07227350/), [L19IL2/TNF in Patients With Basal Cell Carcinoma](https://onco.cc/trials/nct07227870/), [Placebo Microneedles in Healthy Volunteers (Part I) and Efficacy/Safety of Doxorubicin Microneedles in Basal Cell Cancer Subjects (Part II)](https://onco.cc/trials/nct04928222/), [Safety and Efficacy Study for the Treatment of Non-Aggressive Basal Cell Carcinoma With Photodynamic Therapy](https://onco.cc/trials/nct02144077/), [Study to Investigate the Efficacy and Safety of RP1 in Adult Patients With Organ Transplants and Advanced Skin Malignancies](https://onco.cc/trials/nct04349436/), [To Assess the Safety and Efficacy of SP-002 with Vismodegib for the Treatment of Locally Advanced Basal Cell Carcinoma](https://onco.cc/trials/nct06344052/)
- people: [Susana Puig](https://onco.cc/people/susana-puig/)
- key papers: [Esteva 2017: a deep neural network classifies skin cancer at dermatologist level](https://onco.cc/key-papers/paper-esteva-skin-cancer-deep-learning-nature-2017/)
- institutions: [National and Kapodistrian University of Athens, School of Medicine](https://onco.cc/institutions/nkua-athens/), [University of Arizona Cancer Center](https://onco.cc/institutions/arizona-cancer-center/)

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JSON: https://onco.cc/api/v1/entities/basal-cell-carcinoma.json