Treatment

Surgery — wide local excision margins

UK margins are tumour- and risk-specific. Use the margin planner for case-by-case figures.

Melanoma — NICE NG14 §1.5

Stage / pathology	Peripheral margin
Stage 0 / in situ (e.g. lentigo maligna)	At least 5 mm; consider staged excision / Mohs with immunostains or a wider clinical margin for LM, head-and-neck or ill-defined lesions
Stage I, including pT1 and pT2a (1.01–2.0 mm without ulceration)	1 cm
Stage II, including pT2b (1.01–2.0 mm with ulceration), pT3 and pT4	2 cm; 1 cm only if 2 cm would cause unacceptable disfigurement or morbidity

cSCC — BAD 2020

• Low-risk — 4 mm clinical margin, excise into subcutaneous fat.
• High-risk (BWH ≥ T2b, recurrent, immunosuppressed, H-zone, > 2 cm) — 6–10 mm clinical margin OR Mohs micrographic surgery for tissue-sparing in high-risk anatomy.

BCC — BAD 2021

• Low-risk — 4 mm.
• High-risk (morphoeic, infiltrative, micronodular, basosquamous, recurrent, H-zone, > 2 cm, immunosuppressed) — 5–10 mm OR Mohs.

Mohs micrographic surgery

UK practice is guided by BAD disease-specific guidance, BSDS / Mohs service standards and local SSMDT pathways. Strongest indications:

• H-zone of the face (medial canthus, periorbital, nasolabial folds, pre- and post-auricular)
• Recurrent BCC or cSCC
• Aggressive / high-risk histology subtypes
• Tumours with ill-defined clinical margins
• Tumours > 2 cm
• Patients in whom tissue-sparing is critical (eyelid, alar margin)
• Immunosuppressed / OTR cSCC
• DFSP — Mohs (or staged paraffin) is the lowest-recurrence approach
• Lentigo maligna — staged excision / "slow Mohs" with paraffin peripheral margin (some centres use MART-1 frozen sections)

Radiotherapy

Definitive RT

Reserved for elderly / frail patients unfit for surgery, H-zone lesions where surgery would mandate complex reconstruction, and patients declining surgery. Contraindicated in Gorlin syndrome — accelerates BCC formation in the irradiated field.

RCR 2024 dose-fractionation guidance lists example definitive or adjuvant schedules for BCC / cSCC including 32.5–35 Gy in 4–5 fractions for small lesions, 45 Gy in 10 fractions, 50 Gy in 15–20 fractions, 55 Gy in 20 fractions, and 60 Gy in 30 fractions for large fields or areas of poorer radiation tolerance. Choice depends on tumour and field size, site, surrounding structures (lens dose for periorbital), performance status, frailty and life expectancy. Electrons (6–12 MeV with bolus) or orthovoltage / kilovoltage X-rays match the dose to the cutaneous depth.

Adjuvant RT

Strongest indications:

• cSCC — large-calibre or named-nerve PNI; multiply recurrent disease; involved / close margins where re-excision is not feasible; multiple involved nodes or extranodal extension after neck dissection.
• MCC — adjuvant RT to the primary site reduces locoregional recurrence in most cases; nodal-basin RT for SLN-positive disease.
• Aggressive adnexal carcinoma — close margins, LVI, PNI.

Specialty RT

Stereotactic radiosurgery (SRS) for limited melanoma brain metastases; total skin electron beam (TSEB, Stanford six-position) for advanced mycosis fungoides; brachytherapy in selected centres for periorbital / nasal sites.

Systemic therapy by tumour type

Melanoma — adjuvant (resected high-risk disease)

NICE	Drug	Population
TA837	Pembrolizumab	Resected stage IIB / IIC (KEYNOTE-716)
TA766	Pembrolizumab	Completely resected stage III (KEYNOTE-054)
TA684	Nivolumab	Completely resected stage III / IV (CheckMate 238)
TA544	Dabrafenib + trametinib	Completely resected stage III BRAF V600-mutant melanoma (COMBI-AD)
URN 2426	Pembrolizumab neoadjuvant + adjuvant	Stage III macroscopic resectable melanoma, age ≥12 — NHS England routine commissioning; draws on SWOG S1801

Melanoma — unresectable / metastatic

• Anti-PD-1 monotherapy: pembrolizumab (TA366), nivolumab
• Combination ICI: ipilimumab + nivolumab (TA384 / TA400 / TA410 framework) — highest grade 3+ irAE rate (~ 55–60%) but deepest tumour responses
• BRAF/MEK if V600+ : dabrafenib + trametinib (TA396), encorafenib + binimetinib (TA562)
• Uveal melanoma: tebentafusp (TA1027, 9 Jan 2025) for HLA-A*02:01+
• In-transit: electrochemotherapy (IPG446), T-VEC, isolated limb infusion / perfusion

cSCC

• TA802 (29 Jun 2022) — cemiplimab for metastatic / locally advanced cSCC not suitable for curative surgery or RT. Replaced TA592.
• OTRs: ICI use carries 10–40% graft rejection risk in case series — multidisciplinary decision with transplant team.
• Adjuvant cSCC ICI is the subject of ongoing trials (C-POST) and is not yet a routine NICE indication.

BCC

• TA489 (2017) — vismodegib NOT recommended for routine NHS use. It is not a routine NHS-commissioned option; confirm any current NHS England / local funding or IFR route for locally advanced / metastatic BCC and selected Gorlin patients before use.
• Toxicity-limited tolerance (alopecia, dysgeusia, cramps, teratogenicity).

Merkel cell carcinoma

• TA691 (2021) — avelumab first-line for untreated metastatic MCC (JAVELIN Merkel 200). Pembrolizumab has phase 2 evidence in advanced MCC (KEYNOTE-017) but no NICE pembrolizumab MCC TA was identified on live checking; confirm any local or national access route before use.

Cutaneous T-cell lymphoma (MF / Sézary)

• Skin-directed therapy first: potent topical corticosteroids, NB-UVB, PUVA, topical chlormethine (TA720) for adults with stage IA, IB or IIA MF-CTCL.
• TA577 — brentuximab vedotin for CD30+ disease (ALCANZA).
• TA754 — mogamulizumab for relapsed / refractory MF or SS (MAVORIC).
• TSEB for advanced cutaneous disease; ECP for Sézary.

DFSP

• Imatinib may be considered by the specialist sarcoma MDT for unresectable, recurrent or metastatic DFSP, particularly where COL1A1–PDGFB fusion biology supports PDGFRβ inhibition. It can also be used neoadjuvantly in selected very large or anatomically difficult tumours before attempted resection. No positive NICE TA code should be attached to this DFSP indication without live verification.

Immune-related adverse events (irAEs)

Substantial topic — see irAE MCQ bank and the irAE flashcards deck for algorithm-level detail. Key principles:

• Grade-driven management per CTCAE v5.0 + ESMO 2022 algorithm. In broad terms: G1 usually continue with monitoring; G2 hold ICI and start oral prednisolone around 1 mg/kg/day where steroids are indicated; G3 usually hold ICI, admit and use IV methylprednisolone 1–2 mg/kg/day. Important organ-specific exceptions include severe pneumonitis (ESMO uses IV methylprednisolone 2–4 mg/kg/day) and suspected / confirmed myocarditis (pulse IV methylprednisolone 500–1000 mg daily for 3 days). G4 is organ-threatening / life-threatening and usually requires permanent discontinuation and high-acuity care. Always follow the organ-specific algorithm.
• Always exclude infection (especially for colitis — C. diff, CMV in steroid-refractory cases).
• Steroid-refractory colitis — if no improvement after 3–5 days of high-dose steroids, add infliximab 5 mg/kg or vedolizumab 300 mg after infection work-up / gastroenterology input.
• Steroid-refractory hepatitis — mycophenolate mofetil (AVOID infliximab — hepatotoxicity).
• Endocrine irAEs (thyroiditis, hypophysitis, T1DM, adrenalitis) usually allow continued ICI with hormone replacement; replace cortisol BEFORE thyroxine in hypophysitis.
• Myocarditis — rare (<1% severe cases in ESMO) but high-mortality. Stop ICI immediately; admit to level 2/3 care with ECG monitoring; ESMO recommends IV methylprednisolone 500–1000 mg daily for 3 days in confirmed cases, then review response and taper with troponin monitoring. Avoid infliximab for myocarditis; use cardio-oncology MDT escalation.
• 24/7 acute oncology helpline is the safety-net for every patient on ICI.

MDT decision-making

Treatment for skin oncology is multidisciplinary. The core SSMDT team includes dermatology, plastic surgery, clinical oncology, medical oncology, dermatopathology, radiology and a skin cancer specialist nurse. Sub-specialty input (oculoplastics, head & neck, sarcoma, palliative care, clinical genetics) is invited per case. Pathways depend on:

• Tumour biology and stage
• Patient performance status, comorbidity, immunosuppression
• Patient preference (surgery vs RT vs systemic; cosmesis vs function trade-offs)
• Functional anatomical constraints (eyelid, lip, ear, distal digit)
• Geographic and commissioning context (Cancer Alliance, national / local funding eligibility)