# Squamous Cell Carcinoma: Symptoms | World Aid Network > Source: https://worldaidnetwork.org/blog/squamous-cell-carcinoma-skin-uk > Squamous cell carcinoma is the UK's second most common skin cancer, with about 16,000 cases a year, and it can spread. Learn the signs and treatment. Direct Answer Squamous cell carcinoma is the second most common skin cancer in the UK, with approximately 16,000 cases diagnosed each year, and unlike basal cell carcinoma it can spread, so prompt treatment matters. Surgical excision achieves high cure rates. World Aid Network funds cancer treatment for poor patients who cannot afford care. Squamous cell carcinoma (SCC) of the skin is the second most common type of skin cancer in the UK, after basal cell carcinoma (BCC). Approximately 16,000 cases are diagnosed each year, and — unlike the more common BCC — SCC carries a meaningful risk of spreading to lymph nodes and distant organs in approximately 5–10% of high-risk cases. SCC arises from squamous cells — the flat cells that make up the outer layers of the skin (the epidermis). It most commonly develops on sun-exposed areas: the face, scalp, ears, back of the hands, forearms and lower legs. Actinic keratoses (also called solar keratoses) — rough, scaly patches on sun-damaged skin — are the most common precursor lesion. This guide answers the twenty most commonly searched questions about cutaneous squamous cell carcinoma in the UK, drawing on NHS and WHO sources. ## What are risk factors and precursor lesions? Cumulative ultraviolet (UV) radiation exposure is the most important cause of cutaneous SCC — both from sunlight and from artificial UV sources (sunbeds). Fair skin, light eyes and hair, a tendency to burn rather than tan, and a history of extensive sun exposure or sunburn all increase risk. Actinic keratoses (AKs) — rough, scaly, pink or brown patches on chronically sun-damaged skin — are pre-malignant lesions caused by UV-induced DNA damage. The risk of progression from an individual AK to SCC is low (approximately 0.1–0.5% per year), but patients with multiple AKs have a significantly elevated cumulative risk. A particularly important risk group is organ transplant recipients on long-term immunosuppressive therapy — their risk of cutaneous SCC is increased approximately 65–250-fold. SCCs in immunosuppressed patients are more aggressive, more likely to recur and more likely to metastasise. Other risk factors include: chronic scarring conditions (burn scars, chronic ulcers — Marjolin's ulcer); HPV infection (particularly periungual and anogenital SCC); ionising radiation exposure; chemical carcinogens (arsenic); smoking (lip SCC); and pre-existing chronic inflammatory skin conditions such as lichen sclerosus. ## How is it diagnosed? SCC is typically diagnosed on clinical appearance and confirmed by skin biopsy — either incisional (a small sample taken from the lesion) or excisional (the entire lesion removed for examination). Dermoscopy — examination of the skin surface with a handheld illuminated magnifier — can improve clinical diagnostic accuracy. The histopathology report confirms the diagnosis, grades the tumour (well, moderately or poorly differentiated) and assesses features that determine high-risk status. High-risk SCC features include: tumour thickness over 6 mm (Breslow-equivalent depth); poorly differentiated histology; perineural invasion; lymphovascular invasion; diameter over 20 mm; location on the lip, ear, nose or in a scar; and immunosuppression. High-risk SCCs require wider excision margins (6–10 mm), consideration of sentinel lymph node biopsy in some cases, and multidisciplinary team discussion. ## What treatment is available? Surgical excision with clear margins is the primary treatment for most cutaneous SCCs. Standard excision margins are 4–6 mm for low-risk SCC and 6–10 mm for high-risk tumours. Mohs micrographic surgery — a specialised technique in which the tumour is removed in stages with immediate frozen-section margin assessment — achieves the highest cure rates for high-risk SCCs on the face, particularly on the nose, eyelids, ears and lips, where tissue conservation is critical. Radiotherapy is used for patients in whom surgery is not appropriate (frail, elderly, large tumour, refusal of surgery) or as adjuvant treatment after surgery for high-risk cases (positive margins, perineural invasion). For locally advanced (inoperable) or metastatic cutaneous SCC, cemiplimab (Libtayo) — a PD-1 checkpoint inhibitor — is NICE-approved and achieves durable responses in a significant proportion of patients, with an objective response rate of approximately 47% in clinical trials. ### Key takeaways - SCC is the second most common skin cancer in the UK, arising from squamous cells in the skin's outer layer. Unlike BCC, it can metastasise — making prompt treatment essential. - Key warning signs: a firm, rough, scaly or crusted lump on sun-exposed skin; an ulcerated wound that does not heal; a raised pink or flesh-coloured nodule; or a rapidly growing wart-like growth. Any skin lesion that grows, bleeds or does not heal should be assessed by a GP. - Actinic keratoses (rough, scaly patches on sun-damaged skin) are pre-malignant lesions. Treating them — with topical fluorouracil, imiquimod, cryotherapy or PDT — reduces progression risk. - Surgical excision (or Mohs surgery for facial/high-risk SCCs) achieves high cure rates. Cemiplimab (PD-1 inhibitor) is NICE-approved for locally advanced or metastatic SCC. - Organ transplant recipients have up to 250-fold increased SCC risk. They should have annual full-skin examinations by a dermatologist and use strict photoprotection. Your donation funds treatment — not research In the UK, cancer survival rates are among the world's best. In Pakistan, Indonesia and Malaysia, the same cancers kill at far higher rates — because treatment is out of reach for poor patients. World Aid Network funds cancer treatment through locally-licensed oncologists, directly closing that gap. [£10diagnostic tests](/donate?amount=10&cause=cancer)[£25cancer medication](/donate?amount=25&cause=cancer)[£50surgical support](/donate?amount=50&cause=cancer)[£100full treatment](/donate?amount=100&cause=cancer) [Donate Now ](/donate)[View Cancer Emergency Appeal ](/appeal/cancer-emergency) [→ Cancer treatment programmes](/cancer) ## Frequently asked questions What is squamous cell carcinoma (SCC) of the skin? Squamous cell carcinoma (SCC) is a malignant tumour arising from squamous cells — the flat cells that make up the outer layers of the epidermis (the skin's surface layer). It is the second most common type of skin cancer in the UK, with approximately 16,000 new cases diagnosed each year. Unlike basal cell carcinoma, SCC has a meaningful risk of spreading to lymph nodes and distant organs in high-risk cases — making early diagnosis and treatment important. What does squamous cell carcinoma look like? SCC typically appears on sun-exposed areas of the skin (face, scalp, ears, back of the hands, forearms) as one of the following: a firm, rough, scaly or crusted pink, red or skin-coloured lump or nodule that may grow rapidly; a flat, scaly red patch that may resemble eczema or psoriasis but does not resolve; an ulcerated wound or sore that does not heal; a raised, wart-like growth; or a thickened, indurated plaque on a lip (SCC of the lip). SCC in situ (Bowen's disease) appears as a persistent, slowly enlarging, flat, scaly red or pink patch. What is the difference between SCC and BCC? Both SCC and basal cell carcinoma (BCC) are non-melanoma skin cancers caused primarily by UV radiation. BCC arises from basal cells in the deepest layer of the epidermis; SCC arises from squamous cells in the outer layers. BCC almost never metastasises — it is locally destructive but rarely spreads beyond the skin. SCC is more aggressive and carries approximately 5–10% risk of lymph node or distant spread in high-risk cases. SCC requires wider surgical margins than BCC and closer follow-up. What causes squamous cell carcinoma? Cumulative ultraviolet (UV) radiation exposure — from sunlight and sunbeds — is the primary cause, inducing mutations in the TP53 tumour suppressor gene in squamous cells. Other causes include: chronic scarring (burn scars, chronic ulcers — Marjolin's ulcer); HPV infection (particularly for periungual, anogenital and oropharyngeal SCC); ionising radiation; immunosuppression (organ transplant recipients have 65–250-fold elevated risk); arsenic exposure; smoking (lip SCC); and pre-existing inflammatory skin conditions. SCC can also develop in areas of chronic skin damage unrelated to UV. What is an actinic keratosis? Actinic keratoses (AKs) — also called solar keratoses — are rough, scaly, pink, red or brown patches or plaques that develop on chronically sun-damaged skin. They represent a pre-malignant condition caused by UV-induced DNA damage in epidermal keratinocytes. The individual risk of progression from a single AK to SCC is low (approximately 0.1–0.5% per year), but patients with multiple AKs have a significantly elevated cumulative risk. AKs can be treated with cryotherapy, topical fluorouracil (5-FU), imiquimod, ingenol mebutate (Picato), diclofenac gel or photodynamic therapy (PDT). What is Bowen's disease? Bowen's disease is SCC in situ — squamous cell carcinoma confined to the epidermis that has not yet invaded the dermis. It appears as a slowly enlarging, persistent flat, scaly red or pink patch, often on the lower legs (particularly in women) or face. It is caused by UV radiation or HPV. Bowen's disease has a low but real risk of progression to invasive SCC if untreated. Treatment options include cryotherapy, topical 5-fluorouracil cream, imiquimod cream, curettage and cautery, photodynamic therapy (PDT) or surgical excision. How is squamous cell carcinoma diagnosed? Diagnosis is confirmed by skin biopsy — a small incisional biopsy (taking a sample from the lesion) or excisional biopsy (removing the entire lesion). The specimen is examined histopathologically to confirm the diagnosis, assess the degree of differentiation (well, moderate or poor), measure tumour thickness, identify perineural or lymphovascular invasion, and assess excision margins. Dermoscopy improves clinical diagnostic accuracy. High-risk features on histology — thick tumour, poor differentiation, perineural invasion, large diameter — trigger wider re-excision and MDT discussion. What is the treatment for squamous cell carcinoma? Primary treatment is surgical excision with clear margins: 4–6 mm margins for low-risk SCC; 6–10 mm for high-risk tumours. Mohs micrographic surgery achieves the highest cure rates for high-risk SCCs on the face. Radiotherapy is used when surgery is not appropriate or as adjuvant treatment after surgery. For locally advanced (inoperable) or metastatic cutaneous SCC: cemiplimab (Libtayo, a PD-1 checkpoint inhibitor) is NICE-approved and achieves durable responses in a significant proportion (\~47% objective response rate). Pembrolizumab is also approved for some patients. What is Mohs surgery? Mohs micrographic surgery is a specialised surgical technique used for high-risk skin cancers on cosmetically and functionally important sites (face, scalp, ears, nose, eyelids, lips). The tumour is removed in thin horizontal layers; each layer is immediately processed and examined under the microscope before the next layer is removed. This process continues until all margins are clear. Mohs surgery achieves the highest cure rates of any modality (five-year recurrence rates under 3% for primary facial SCC), while conserving as much normal skin as possible. Can SCC spread? Yes. SCC can spread to regional lymph nodes (lymphatic spread) and, less commonly, to distant organs (haematogenous spread — most commonly lung, liver, bone and brain). The risk of metastasis depends on tumour characteristics: low-risk SCC (small, well-differentiated, thin, non-immunosuppressed patient) has a very low metastatic risk (approximately 1–2%); high-risk SCC (large, poorly differentiated, deeply invasive, perineural invasion, immunosuppressed patient) has a metastatic risk of 5–10% or higher. Metastatic cutaneous SCC requires systemic treatment with cemiplimab. Who is at highest risk of SCC? The highest-risk groups are: people with a history of extensive UV exposure (outdoor workers, sunbed users, those who have lived in high-UV climates); fair-skinned people who burn easily; organ transplant recipients on immunosuppressive therapy (65–250-fold elevated risk — SCC is 3–5 times more common than BCC in this group, the reverse of the immunocompetent population); HIV-positive individuals; patients with chronic scarring conditions or chronic ulcers; those with multiple actinic keratoses; and people who have had previous SCC (10–25% develop a second SCC within 2 years). What is the survival rate for SCC? For most cutaneous SCCs, prognosis is excellent — five-year survival for low-risk, localised SCC treated with surgery is over 95%. High-risk SCCs with lymph node involvement have approximately 50–70% five-year survival. Distant metastatic cutaneous SCC has a poor prognosis — historically five-year survival was under 30%, but cemiplimab immunotherapy has significantly improved outcomes for patients achieving durable responses. The most important factors affecting prognosis are tumour size, depth, differentiation, perineural invasion, lymph node status and immune function. What is the difference between SCC and melanoma? Melanoma arises from melanocytes (pigment-producing cells) and is the most dangerous type of skin cancer due to its high metastatic potential. SCC arises from squamous cells in the outer epidermis. Melanoma typically presents as a pigmented lesion (brown, black, multi-coloured) — though amelanotic (non-pigmented) melanoma exists. SCC typically presents as a non-pigmented lump, ulceration or scaly plaque. Melanoma is more likely to spread early. Both require prompt surgical excision. Any concerning pigmented or non-pigmented skin lesion should be assessed urgently by a GP using the ABCDE criteria. How can I prevent squamous cell carcinoma? UV radiation reduction is the primary prevention strategy: use SPF 30+ broad-spectrum sunscreen daily on sun-exposed areas; wear protective clothing (long sleeves, wide-brimmed hat); avoid sunbeds; seek shade during peak UV hours (11am–3pm); and never allow sunburn. Treat actinic keratoses promptly to reduce SCC risk. Organ transplant recipients should be counselled about their elevated risk, use strict sun protection, and attend annual full-skin surveillance with a dermatologist. Regular self-examination of the skin helps with early detection. What is cemiplimab for SCC? Cemiplimab (Libtayo) is a PD-1 checkpoint inhibitor immunotherapy drug approved by NICE for locally advanced (inoperable) or metastatic cutaneous squamous cell carcinoma that cannot be treated with surgery or radiotherapy. It works by blocking the PD-1 protein on T cells, re-activating the immune system's ability to recognise and attack cancer cells. Clinical trials showed an objective response rate of approximately 47%, with durable responses in many patients. It is given as an intravenous infusion every three weeks. What is the difference between SCC and SCC in situ? SCC in situ (also called Bowen's disease or intraepidermal SCC) is squamous cell carcinoma that is confined entirely to the epidermis — it has not yet broken through the basement membrane into the dermis. SCC in situ has essentially zero metastatic risk in this stage. Invasive SCC has breached the basement membrane and entered the dermis, giving it access to blood vessels and lymphatics — and therefore the capacity to spread. SCC in situ is treated more conservatively (topical treatment, cryotherapy, PDT) compared with invasive SCC, which requires surgical excision. Do transplant recipients get more skin cancer? Yes, significantly so. Organ transplant recipients on long-term immunosuppressive therapy have a 65–250-fold increased risk of cutaneous SCC and a 10-fold increased risk of BCC, compared with the immunocompetent population. This is the reverse of the general population pattern (where BCC is far more common than SCC). Transplant-associated SCCs are more aggressive — thicker, more likely to recur and more likely to metastasise. All organ transplant recipients should be counselled on sun protection, perform regular skin self-examination and receive annual full-skin surveillance by a dermatologist from the time of transplant. How does SCC affect people in developing countries? Squamous cell carcinoma of the skin is globally the most common cancer in populations living close to the equator with high UV exposure. In many parts of Africa, the Middle East and South Asia — the regions WAN operates in — SCC presents at a more advanced stage due to delayed medical assessment and limited dermatology services. Cemiplimab immunotherapy for advanced SCC is unaffordable and unavailable in these settings. Surgical excision with adequate margins requires skin pathology services that are absent in many district hospitals. World Aid Network funds cancer treatment through locally-licensed oncologists. [**Medically reviewed by Mr Mohamed Mohyudin**MBChB BSc MSc FRCOphth CCT · GMC No. 7039600 · Consultant Ophthalmic Surgeon](https://mohamedmohyudin.co.uk/) This article was reviewed by the World Aid Network editorial team for factual accuracy against WHO, NHS, HMRC and Charity Commission sources. World Aid Network is a UK Charitable Incorporated Organisation (charity registration in progress), governed by named trustees. ### Fund cancer treatment for those who cannot afford it In high-UV regions of the world, SCC is a major cancer burden — but dermatology services and effective treatments are unavailable to the rural poor. World Aid Network funds cancer treatment through locally-licensed oncologists. 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