Squamous Cell Carcinoma (SCC)

What Is Squamous Cell Carcinoma?

SCC arises from the squamous cells in the upper layers of the epidermis. It is driven by cumulative UV damage over a lifetime, which is why it is common in outdoor workers, farmers, sportspeople and anyone with heavily sun-exposed skin. SCC can also develop on the lips, in scars, and on areas previously treated with radiation.

SCC is closely linked to actinic keratosis (AK) — the rough, scaly sun spots that many Australians develop. An actinic keratosis is considered a pre-cancerous lesion: a small proportion progress to squamous cell carcinoma if left untreated. Treating AKs is one way of reducing future SCC risk.

What Does SCC Look Like?

• A thickened, rough or scaly lump that feels firm — like a small crusty horn or a wart that keeps growing
• Rapid growth — noticeable change over weeks to months, unlike the slow pace of a BCC
• Tenderness or pain — SCCs are often sore to touch, unlike most other sun spots
• Easy bleeding — the surface may ulcerate, ooze or bleed with minor friction
• A persistent crusted sore that does not heal within about 4 weeks
• On the lips: a persistent scaly patch or sore, especially on the lower lip

Risk Factors

• Cumulative lifetime sun exposure — outdoor occupations and outdoor hobbies
• Fair skin, light hair and a tendency to burn rather than tan
• Untreated actinic keratoses and widespread field sun damage
• A previous SCC or other skin cancer
• Immunosuppression — including transplant recipients and certain medications
• Older age, male sex, smoking, and long-term wounds or scars in sun-exposed skin

Why SCC Needs Prompt Treatment

The key difference between SCC and BCC is metastatic potential. Most SCCs caught early are cured by simple treatment alone; but an SCC left to grow for months can invade deeper tissue and, in a minority of cases, spread to lymph nodes and beyond. Higher-risk features include tumours larger than 2 cm, tumours on the lip or ear, tumours arising in scars, thick tumours, and SCCs in immunosuppressed patients.

This is why an SCC is generally treated with definitive removal rather than observation, and why your SCC doctor may recommend staged margin-controlled surgery for tumours on the head and neck. Prompt SCC treatment is not about panic — it is about keeping a curable problem simple. If you notice a spot with any of the features listed above, arrange an SCC check with your doctor, because the difference between a straightforward excision and a more complex skin cancer surgery is often simply time.

SCC Treatment Options

• Surgical excision — the standard SCC surgery: the tumour is removed with a measured margin of healthy skin and the wound closed directly, with a flap, or with a graft
• Curettage and cautery — scraping and sealing the lesion; appropriate for small, low-grade SCCs on the trunk and limbs
• Staged margin-controlled surgery — step-by-step removal with same-day microscope checks of all margins; the preferred approach for higher-risk SCCs on the face. Learn more about staged margin-controlled surgery
• Cryotherapy — suitable only for selected low-grade lesions, and only when SCC has been excluded or the diagnosis is certain
• Topical and field treatments — prescription creams or PDT for actinic keratosis to reduce the surrounding field of sun-damaged skin that feeds future SCCs

For the small group of higher-risk or advanced SCCs, additional imaging, radiotherapy or referral to a larger cancer centre may be arranged. Your treating doctor will explain whether any of this applies to you.

Follow-Up After SCC Treatment

Because SCC can recur locally and people who have had one SCC are at increased risk of further skin cancers, structured follow-up is part of good SCC treatment. The treated site is usually reviewed within three to six months, and a full-body skin check is recommended every six to twelve months thereafter. Patients on immunosuppressive medication may need more frequent reviews, and anyone noticing a new tender, scaly or bleeding spot between appointments should book an SCC check promptly rather than waiting.

Reducing Your SCC Risk

• Daily broad-spectrum SPF 50+ sunscreen on all sun-exposed skin, reapplied during the day outdoors
• Wide-brimmed hats and long sleeves for outdoor work and sport
• Having actinic keratoses treated rather than watched — clearing the field of pre-cancerous sun spots lowers the chance of future SCC
• Six-to-twelve-monthly skin checks if you have had an SCC, extensive sun damage, or take immunosuppressive medication

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