A Guide to Squamous Cell Carcinoma (SCC)

Medically Reviewed By Clare Wightman MS, PAC
Was this helpful?
46

Squamous cell carcinoma (SCC) is a type of skin cancer that typically develops on sun-damaged skin. SCC is typically superficial. However, it can reach deep into the skin and damage nerves, blood vessels, and other subcutaneous structures. Some cases of SCC may resolve with treatment, such as curettage and electrodessication or a topical chemotherapy cream. Aggressive or deep-growing cases may require surgical removal and additional treatments, such as radiation therapy.

Read on to learn more about the causes, symptoms, and treatments for squamous cell carcinoma.

What are the causes of squamous cell carcinoma?

A man with light skin shading his eyes from the sun with his hand
Diane Villadsen/Stocksy United

SCC starts with out-of-control cell growth. This unusual growth results from changes or mutations in the skin’s squamous cells.

Excessive exposure to UV light is one of the main triggers for SCC mutations. UV light damages the DNA in skin cells a little bit with each exposure.

The damage accumulates with time until the body can no longer repair it. This damage can take years to turn into cancer. However, people with more exposure or prolonged exposure can develop cancer more quickly.

Other factors that may contribute to the development of SCC include:

  • exposure to certain chemicals, such as tar in cigarettes
  • severe skin damage from burns
  • chronic ulcers or sores
  • human papillomavirus virus (HPV)
  • immunosuppressive medications, which could lead to more aggressive SCC

What are the symptoms of squamous cell carcinoma?

Squamous cell carcinoma pictures

1-actinic-keratosis-300x169.jpg

Squamous cell carcinoma can often develop from actinic keratoses, which can be scaly, dry, or raised patches of skin.

CLS Digital Arts/Shutterstock

2-squamous-cell-carcinoma-1296x728-gallery-slide3-300x169.jpg

Squamous cell carcinoma may look like open sores.

Reproduced with permission from ©DermNet NZ www.dermnetnz.org 2022

3-hg-squamous-cell-carcinoma-300x169.jpg

In some cases, squamous cell carcinoma can protrude from the skin in horn-like growths.

BSIP/Universal Images Group via Getty Images

SCC usually appears on sun-damaged skin. However, it can occur anywhere, including the palms of the hands.

SCC often starts as an actinic keratosis, a type of skin lesion. Actinic keratosis patches may appear as pink-brown, scaly, flat spots of dry skin. Not all actinic keratosis spots become cancerous. Researchers estimate that around 8% of actinic keratoses in people with average immune system function become cancer.

Learn more about actinic keratosis.

When actinic keratosis does become SCC, the lesions may look like red or pink raised, round growths.

Other possible presentations for this condition are:

  • brown spots resembling age spots
  • dome-shaped, firm growths that may be tender
  • horn-like growths that may look like small rhinoceros horns
  • open sores that may have raised borders
  • sores that develop on old scars
  • wart-like growths
  • discolored, scaly patches

For people with darker skin tones, these lesions can also be:

  • yellowish
  • white
  • brown
  • black
  • reddish
  • pink

Some people experience itchiness, tenderness, and pins-and-needles sensations around the affected area. Numbness may also occur.

Sometimes, SCC can affect the inside of your mouth or your nails. Inside the mouth, it can look like a sore or a white area. It can also look like a dark streak under the nail or cause the nail to disappear.

If SCC occurs in the genital area, it may be wart-like or a raised, pink or brownish patch.

How do doctors diagnose squamous cell carcinoma?

To diagnose SCC, doctors may begin by asking you about your medical history and performing a physical examination. A skin biopsy of the affected area will be necessary to confirm a diagnosis.

What are the treatments for squamous cell carcinoma?

In the early stages, treatment is highly effective at managing and curing SCC. In most cases, doctors can remove the cancer during an office procedure.

For low-risk SCC, doctors may use a topical treatment and photodynamic therapy to remove cancerous cells. Some people may also be able to apply topical chemotherapy creams at home.

In cases where surgical removal is necessary, doctors may use one of the following techniques:

  • excision, which cuts out the cancer along with a ring of healthy skin
  • Mohs surgery, which removes the cancer one layer at a time until cancer cells are no longer present
  • curettage and electrodessication, which removes the growth and uses an electrical current to remove any remaining cancer cells

Radiation therapy is an alternative when surgery is not an option. Doctors may also recommend radiation therapy in addition to surgery.

When SCC spreads, more aggressive treatment is necessary. These advanced cancers may require a combination of:

  • surgery
  • radiation therapy
  • immunotherapy
  • systemic chemotherapy

Learn more about SCC treatment options.

What is the outlook for people with squamous cell carcinoma?

Early diagnosis and treatment are crucial to improving the outlook for people with SCC. In the early stages, treatment for SCC is very effective.

Without treatment, SCC may spread and cause complications. Later stages will also require more aggressive treatments.

What are some potential complications of squamous cell carcinoma?

SCC is slow-growing and treatable in its early stages. Without treatment, however, it can spread deep into the skin.

When squamous cell tumors grow deep, they can damage nerves, blood vessels, and other tissues under the skin. SCC can also spread to lymph nodes and other areas of the body.

What are the risk factors for squamous cell carcinoma?

UV light exposure from the sun or indoor tanning equipment is the primary risk factor for SCC. People who live in areas with intense year-round sunshine tend to have higher exposure and risk of skin cancer.

Other SCC risk factors include:

  • light skin, light eyes, and naturally light (undyed) hair
  • history of skin cancer or blistering sunburns during adolescence
  • actinic keratosis
  • skin that rarely tans
  • skin that freckles or burns easily
  • weakened immune system due to a medical condition or medication
  • history of HPV
  • history of chronic skin infections or inflammation from burns, scars, or other conditions

Can you prevent squamous cell carcinoma?

The main way to lower your risk of developing SCC is to avoid exposure to UV light. The Skin Cancer Foundation recommends the following to reduce UV light exposure and damage that can lead to skin cancer:

  • Apply a daily UVA/UVB sunscreen with a sun protection factor (SPF) of 30 or more.
  • Avoid indoor tanning.
  • Move activities indoors when the UV index is high.
  • Schedule outdoor activities before 10 a.m. and after 4 p.m.
  • Use or create shade when outside.
  • Wear hats, sunglasses, and clothing with an ultraviolet protective factor (UPF).

None of these strategies offer total protection from UV light by themselves. As such, it may be best to combine several of them.

Your skin cancer prevention routine should also include regular skin checks. You can either conduct these on your own or with a medical professional.

Other frequently asked questions

These are a few other common questions people ask about SCC. Clare Wightman, MS, PA-C, has reviewed the answers.

What is the survival rate for squamous cell carcinoma?

Treatment is very effective for curing early stage SCC. However, advanced or metastasized SCC can result in poorer outcomes, with a 5-year survival rate of less than 40%.

How quickly does squamous cell carcinoma spread?

SCC spreads slowly. However, without prompt treatment, it can grow deep into the skin and become harder to treat.

Do you need chemotherapy for squamous cell carcinoma?

You may need chemotherapy to treat SCC if it has spread to lymph nodes or distant parts of the body.

Is squamous cell carcinoma common?

SCC is the second most common type of skin cancer after basal cell carcinoma. Researchers estimate that more than a million SCC diagnoses occur in the United States each year.

Summary

Because SCC can spread, it is important to contact your doctor promptly if you notice a new or changing skin lesion. If you have a high risk of developing skin cancer, you may need regular screenings with your doctor. This is also true if you have already had skin cancer.

Ask your doctor how often to perform self-exams and schedule professional skin exams.

Was this helpful?
46
Medical Reviewer: Clare Wightman MS, PAC
Last Review Date: 2022 Oct 7
View All Skin Cancer Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Howell, J. Y., et al. (2022). Squamous cell skin cancer. https://www.ncbi.nlm.nih.gov/books/NBK441939/
  2. Marques, E., et al. (2022). Actinic keratosis. https://www.ncbi.nlm.nih.gov/books/NBK557401/
  3. Skin cancer prevention. (n.d.) https://www.skincancer.org/skin-cancer-prevention/
  4. Skin cancer types: Squamous cell carcinoma overview. (n.d.). https://www.aad.org/public/diseases/skin-cancer/types/common/scc
  5. Tam, S., et al. (2020). Association of immunosuppression with outcomes of patients with cutaneous squamous cell carcinoma of the head and neck. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902183/
  6. Treating squamous cell carcinoma of the skin. (2020). https://www.cancer.org/cancer/basal-and-squamous-cell-skin-cancer/treating/squamousl-cell-carcinoma.html