What is squamous cell carcinoma?

Squamous cell carcinoma (SCC) is a type of skin cancer that starts in the top layer of your skin. It is the second most common type of skin cancer. The most common type is basal cell carcinoma (BCC).

SCC can develop anywhere on your body. It usually grows in areas that get a lot of sun exposure, such as your:

• face, ears, neck or scalp (if you are bald or have thin hair)
• forearms and the back of your hands
• lower legs

If not treated, SCC can grow quickly. It can spread and even cause death. Every year, people in Australia die from SCCs.

What are the types of squamous cell carcinoma?

SCC can be divided into different types based on how much it has grown or spread.

• Actinic keratosis — are early skin changes that may turn into SCC if not treated.
• SCC in situ (Bowen's disease) — is an early type of SCC. It has only grown in the top layer of your skin.
• Invasive SCC — is when the cancer has spread into the deeper layers of your skin.
• Metastatic SCC — is when the cancer has spread to other parts of your body.

If SCC is not treated early, it may grow and spread to other parts of your body.

What are the symptoms of squamous cell carcinoma?

The first sign of SCC is usually a thick, scaly area on your skin that does not heal. It may bleed or form a sore. It tends to grow slowly.

If you have SCC in your genital area, it may look like a small sore that doesn't go away.

As your SCC grows into the deeper layers of your skin, it may grow faster and become painful.

What causes squamous cell carcinoma?

SCC happens when squamous cells in the top layer of your skin grow out of control. This is often caused by too much sun exposure, which damages the skin cells.

You may have a higher risk of developing SCC if you:

• are over 60 years of age
• have a fair skin tone
• spend a lot of time in the sun, such as working outdoors
• have sunspots (solar keratoses)
• have a weakened immune system
• have an HPV (human papillomavirus) infection
• are male

When should I see my doctor?

See your doctor if you:

• are worried about skin cancer
• notice any changes on your skin
• notice any suspicious spots

It's important to check your skin regularly, especially if you are at high risk of skin cancer. Look for changes in shape, colour and size of any spots or moles on your skin.

You can use the ABCDE guide to check for suspicious spots:

• Asymmetry — your spot is uneven or irregular, not round or oval
• Border — the edges of your spot are uneven
• Colour — your spot has an unusual or uneven colour
• Diameter — your spot is larger than 6mm
• Evolving — your spot is changing in colour, size or shape

Skin cancer screening

There are no specific guidelines for skin cancer screening. Based on your personal risk, your doctor may discuss with you how often you should be checked.

• When you see your doctor for other health issues, ask them if you need a skin check — this is called 'opportunistic screening'.
• If you are at high risk of skin cancer, see your doctor for a skin check at least every 12 months.
• If you have had an organ transplant, you should have yearly checks with a specialist.

Read the article 'should I be checked for skin cancer'?

How is squamous cell carcinoma diagnosed?

If your doctor thinks you may have SCC, they may:

• ask about your medical history and symptoms
• check your skin
• take a small sample of your spot (biopsy) to test in a lab to confirm if it's SCC

You doctor may refer you to a dermatologist (skin specialist) for further testing or treatment.

How is squamous cell carcinoma treated?

Your doctor can treat SCC in several ways, such as:

• surgical removal under local anaesthetic, followed by a microscopic check to make sure all the cancer has been removed
• scraping it off and sealing the wound with an electric needle or liquid
• freezing the SCC with a liquid

It is usually possible to completely remove your SCC. The best treatment for you will depend on the size and location of your SCC.

If your SCC has spread, your doctor may suggest treatments, such as:

• immunotherapy
• chemotherapy
• radiotherapy

If you've had SCC, you are at a higher risk of developing another skin cancer. It's very important to protect your skin from the sun.

What are the complications of squamous cell carcinoma?

If your SCC is not treated early, it may grow and spread to other organs in your body.

Can squamous cell carcinoma be prevented?

You can prevent SCC by protecting your skin from ultraviolet (UV) radiation. This means protecting your skin from the sun.

Here are some ways to help prevent SCC:

• Avoid sunburn by staying out of the sun when the UV Index is higher than 3, especially in the middle of the day.
• Seek shade, wear a hat, sunglasses and clothing that protects you from the sun.
• Always use an SPF30+ (or higher) sunscreen.
• Avoid tanning salons.

If you are at high risk of skin cancer, your doctor may prescribe specific vitamins to help reduce your risk.

Resources and support

• SunSmart offers a global UV app for information about sun safety.
• Cancer Council Australia provides information about sun safety, checking for and preventing skin cancers.
• Bureau of Meteorology UV Index provides information about the UV index and sun protection hours.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Other languages

• Cancer Council has a translated guide about basal and squamous cell carcinomas.

Looking for information for Aboriginal and/or Torres Strait Islander people?

• Our Mob and Cancer has information about sun protection for Aboriginal and/or Torres Strait Islander people.