What is Squamous Cell Carcinoma (SCC)? Causes, Symptoms and Treatment

Squamous cell carcinoma (SCC) is the second most common form of skin cancer, second only to basal cell carcinoma. Hundreds of thousands of people are diagnosed with SCC worldwide every year. Fortunately, SCC is curable in most cases when detected early.

In this article, we explain exactly what squamous cell carcinoma is, what it looks like, who is at risk, and what treatment options are available.

What is squamous cell carcinoma (SCC)?

Squamous cell carcinoma (SCC) is a malignant tumour disease that develops from the squamous cells in the epidermis – the outermost layer of the skin. Squamous cells flatten out and form the protective outer layer of the skin, and when these cells mutate and grow uncontrollably, SCC develops.

SCC grows slowly in most cases and rarely spreads to other parts of the body. However, untreated SCC can penetrate deep into the skin and in rare cases form metastases, especially in people with weakened immune systems.

What does squamous cell carcinoma look like?

SCC can appear in several forms:

Red, scaly patch: A rough, thick or crusted area on the skin — often on sun-exposed areas such as the face, ears, neck or hands.
Firm, wart-like bump: A firm bump with a reddish colour and rough, scaly surface.
A sore that does not heal: An open sore that bleeds, oozes or forms a crust and does not heal despite treatment.
Flat pink or red patch: With a slightly raised, rough edge and often a scaly surface.

SCC most commonly occurs on sun-exposed areas: face, ears, lips, neck, hands and forearms. However, it can appear anywhere on the body.

Why does squamous cell carcinoma occur?

The primary cause of SCC is chronic exposure to ultraviolet (UV) radiation from the sun or tanning beds. UV radiation damages the DNA in skin cells, and when this damage accumulates over time in the squamous cells, they can begin to grow uncontrollably.

Main risk factors

Fair skin tone and light eyes: People with fair skin have less melanin protection against UV radiation.
Chronic sun exposure: Prolonged time in the sun over many years significantly increases the risk.
Sunburns: Especially severe sunburns in childhood and teenage years increase the risk.
Tanning beds: Use of tanning beds before the age of 20 significantly increases the risk.
Weakened immune system: Organ transplant recipients, HIV patients and people on immunosuppressive treatment have a 10–100 times higher risk.
Precancerous lesions: Actinic keratoses (rough, scaly patches) are precursors to SCC and should be monitored.

Who gets squamous cell carcinoma?

SCC can affect anyone, but certain groups are significantly more vulnerable:

People over 50 years old: The risk increases significantly with age, as UV damage accumulates over time.
Men: Men generally have a higher incidence of SCC than women, partly due to differences in sun exposure and protective habits.
People with fair skin: Especially people of Celtic or Northern European descent and those who burn easily.
The immunocompromised: Organ transplant recipients and people with severe immunosuppression are at particular risk.

What can you do about squamous cell carcinoma?

SCC is highly treatable, especially when detected early. Several effective treatment options are available:

🔬 Surgical removal

The standard treatment for most SCC cases. Standard surgical excision or MOHS surgery (micrographic surgery) is used, especially on the face to preserve as much healthy skin as possible.

☀️ Radiation therapy

Used when surgery is not possible, or for high-risk SCC that cannot be adequately removed with surgery alone.

💊 Topical medications

Creams such as 5-fluorouracil (5-FU) or imiquimod can be used for superficial SCC or actinic keratoses.

💡 Photodynamic therapy (PDT)

A light-activated treatment that destroys cancer cells. Typically used for superficial SCC.

Medical classification: Squamous cell carcinoma is classified as 2C31 in the WHO's International Classification of Diseases (ICD-11). It is a skin cancer arising from squamous cells, often presenting as scaly, red patches. Surgical removal is the primary treatment.

Preventing squamous cell carcinoma

Prevention is the best strategy against SCC. Here are the most important precautions:

Use sunscreen year-round: Choose SPF 30 or higher and reapply every two hours during sun exposure.
Avoid tanning beds: Tanning beds significantly increase the risk and should be avoided entirely.
Protective clothing: Wear a hat, sunglasses and long-sleeved shirts during intense sun exposure.
Avoid midday sun: Seek shade between 12:00 and 15:00, when UV radiation is strongest.
Regular self-examination: Check your skin monthly for new or changing spots, especially if you are in a risk group.
Actinic keratoses: Have actinic keratoses (rough, scaly patches) examined and treated before they develop into SCC.

Frequently asked questions

Is squamous cell carcinoma deadly?

SCC is rarely deadly when detected early. The five-year survival rate for localised SCC is above 95%. However, untreated SCC can in rare cases spread (metastasise) and become life-threatening, especially in the immunocompromised.

What is the difference between BCC and SCC?

Both BCC and SCC are skin cancers, but they develop from different cell types. BCC (basal cell carcinoma) develops from basal cells in the lower part of the epidermis and grows very slowly. SCC (squamous cell carcinoma) develops from squamous cells on the surface of the epidermis and has a somewhat higher risk of spreading than BCC.

When should I contact a dermatologist?

Contact a dermatologist if you notice a sore that does not heal within 4–6 weeks, a new or changing spot on the skin, or a rough, scaly patch that is growing or changing. Early diagnosis is crucial for successful treatment.

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Disclaimer: This article is for informational purposes only and does not replace professional medical advice. Always consult a dermatologist for personal guidance.