Cutaneous Squamous Cell Carcinoma: Surgery, Creams, and All Your Treatment Options

What Is Squamous Cell Carcinoma of the Skin?

Cutaneous squamous cell carcinoma (SCC) is a cancer that starts in the flat, scaly cells of the outer layer of your skin (the epidermis). It is the second most common skin cancer after basal cell carcinoma, making up about 20% of all non-melanoma skin cancers. SCC most often develops from sun-damaged skin or from a precancerous condition called actinic keratosis.

Most SCC is localized and highly curable. However, some tumors have features that make them more likely to come back or spread to lymph nodes or other organs. Understanding these “high-risk” features helps you and your doctor choose the right treatment from the start.

What Makes an SCC “High Risk”?

Not all SCCs are equal. Your doctor will assess several factors to figure out whether your tumor is low-risk or high-risk:

• Size: Tumors wider than 2 centimeters (about the width of your thumbnail) are high-risk
• Depth: Tumors that have grown deeper than 4 millimeters into the skin are high-risk
• Location: SCC on the lip, ear, eyelid, nose, or genitals behaves more aggressively than SCC on the trunk or limbs
• Grade: Poorly differentiated tumors (cancer cells that look very abnormal) are more dangerous
• Perineural invasion: When cancer cells grow along nerve pathways, the tumor is much more likely to come back. This occurs in about 5–10% of cases but signals a need for more aggressive treatment
• Immune status: People who take medications to suppress their immune system (such as organ transplant recipients) develop more aggressive SCCs that are more likely to spread
• Prior radiation exposure or chronic wounds: SCC arising in irradiated skin or a long-standing wound (Marjolin’s ulcer) is especially aggressive

Surgical Treatment Options

Standard Surgical Excision

Surgery is the main treatment for most SCCs. Standard excision means your surgeon removes the tumor along with a surrounding ring of normal skin (the margin). For low-risk SCC, margins of 4–6 millimeters are used. For high-risk tumors, margins of 6–10 millimeters are needed. The removed tissue is sent to a lab for analysis.

Cure rates with standard excision are about 95% for low-risk SCC and 85–90% for high-risk tumors. If you have a small, low-risk tumor in a non-cosmetically sensitive area, standard excision is usually the right choice.

Mohs Micrographic Surgery

Mohs surgery is a specialized technique where the surgeon removes the tumor one thin layer at a time and checks each layer under a microscope during the procedure. This process continues until no cancer cells remain. It offers two big advantages: it removes every cancer cell (cure rates exceed 99% for primary SCC and 95% for recurrent tumors) and it spares as much healthy skin as possible.

Mohs surgery is the best choice when:

• The tumor is on the face, ears, nose, eyelids, lips, or genitals
• The tumor is larger than 2 cm or deeper than 4 mm
• The pathology report shows perineural invasion or poor differentiation
• You are immunosuppressed
• The cancer has come back after previous treatment

Non-Surgical Treatment Options

For very early-stage SCC that has not grown deeply into the skin (especially a type called Bowen’s disease, or SCC in situ), non-surgical options are available. These are not appropriate for invasive SCC with high-risk features.

Topical 5-Fluorouracil (5-FU) Cream

5-FU cream, applied twice daily for 2–6 weeks, causes inflammation that destroys abnormal cells near the skin surface. It achieves response rates of 70–85% for early, thin SCC in situ. Side effects include redness, irritation, and peeling—which is actually a sign the medication is working. Recurrence rates of 10–20% are higher than with surgery, so this approach is reserved for carefully selected patients who are followed closely afterward.

Imiquimod Cream (5%)

Imiquimod works differently from 5-FU—it activates your immune system to attack cancer cells. Applied 3–5 times per week for 4–16 weeks, it achieves response rates of 75–90% for early SCC in situ. Side effects include local redness and irritation but are generally less severe than with 5-FU. Like topical 5-FU, imiquimod is best for thin, early disease where close follow-up is possible.

Photodynamic Therapy (PDT)

PDT involves applying a light-sensitive medication to the skin, then activating it with a specific wavelength of red light. The reaction destroys abnormal cells. PDT achieves complete response rates of 75–90% for thin SCC in situ and early-stage SCC, with the added benefit of excellent cosmetic results. It works well for treating large areas affected by field cancerization (widespread sun damage). Multiple sessions are sometimes needed. PDT is especially valuable for organ transplant patients who have many lesions across a wide area.

Radiation Therapy

When surgery is not possible (due to medical conditions, age, or tumor location), radiation therapy is a strong alternative. A course of radiation—typically delivered in daily sessions over 3–4 weeks—achieves tumor control rates of 85–95% for SCC. Radiation is also used after surgery if the pathology report shows incomplete removal or perineural invasion. Disadvantages include a prolonged treatment schedule and risk of long-term skin changes at the treated site.

Advanced and Systemic Treatments

For advanced SCC that has spread to lymph nodes or other organs, or for cases where surgery and radiation are not possible, systemic therapies are used:

• Cemiplimab (Libtayo): An immunotherapy drug (checkpoint inhibitor) approved for advanced cutaneous SCC. It works by releasing the brakes on your immune system so it can attack cancer cells. Response rates of about 47% have been reported in clinical trials.
• Pembrolizumab (Keytruda): Another immunotherapy option for advanced SCC not curable by surgery or radiation.
• Chemotherapy: Platinum-based regimens may be used for metastatic SCC, though response rates are lower than with immunotherapy.

After Treatment: Monitoring and Follow-Up

Even after successful treatment, follow-up is important. SCC can recur at the original site or spread to regional lymph nodes, especially in high-risk cases. Your dermatologist will likely recommend:

• Skin exams every 3–6 months for the first 1–2 years
• Annual exams thereafter
• Lymph node checks at each visit if you had a high-risk tumor
• Imaging (ultrasound or CT scan) if there is any concern about lymph node involvement

When to See a Dermatologist

• A rough, scaly patch or sore that does not heal within a few weeks
• A firm bump or raised area that bleeds easily
• A wart-like growth that persists or changes
• Any spot on the lip, ear, or face that is growing
• A previously treated SCC site looks different or a new spot appears nearby
• You are immunosuppressed and develop any new or changing skin lesions

Frequently Asked Questions

Is SCC more dangerous than basal cell carcinoma?

Generally, yes. While both are highly curable when caught early, SCC has a greater potential to spread to lymph nodes or other organs compared to basal cell carcinoma. The overall metastasis rate for cutaneous SCC is about 2–5%, but this rises significantly with high-risk features like large size, perineural invasion, or immunosuppression.

Can I use a cream instead of having surgery?

Only for very early, surface-level SCC (SCC in situ or Bowen’s disease). If your SCC has grown into the deeper layers of skin, surgery is necessary. Your dermatologist will review your biopsy results and advise you on whether non-surgical treatment is appropriate for your specific situation.

What does it mean if the margins were not clear after surgery?

If the pathology report shows cancer cells at the edge of the removed tissue (positive margins), not all the cancer was removed. Your doctor will likely recommend re-excision (removing more tissue) or Mohs surgery to achieve clear margins and reduce the risk of recurrence. This is an important conversation to have promptly after surgery.

I am on immunosuppressive medications after an organ transplant. Am I at higher risk?

Yes, significantly. Transplant recipients have a 65–250 times higher risk of developing SCC compared to the general population, and their tumors are often more aggressive. If you are immunosuppressed, you should have full-body skin exams at least annually (many specialists recommend every 3–6 months) and be especially vigilant about sun protection.

References

Trusted Resources

• American Academy of Dermatology: Squamous Cell Carcinoma
• Skin Cancer Foundation: Squamous Cell Carcinoma
• Mayo Clinic: Squamous Cell Carcinoma

Always consult a board-certified dermatologist for diagnosis and treatment of any skin concern. This article is for educational purposes and does not replace individualized medical advice.