Patient information from BMJ

Skin cancer (squamous cell)

Last published:Jun 02, 2023

Squamous cell skin cancer usually looks like a crusted lump on the skin. It can be sore and tender and usually gets bigger over time. The lump won’t heal or go away without treatment. But it can be cured with surgery in most people.

You can use our information to talk to your doctor about which treatments are right for you.

What is squamous cell skin cancer?

As its name suggests, this type of skin cancer starts in the squamous cells of your skin. These cells sit in the top layer of your skin, just under the surface. Sometimes they get damaged, usually by too much sun.

Unlike normal skin cells, these damaged cells don’t die off and get replaced by new cells. Instead they stay on your skin and multiply.

These cells may form a lump, which may be a tumour (a squamous cell cancer). If the tumour isn't treated it can damage the tissues nearby and spread to other parts of your body.

Squamous cell skin cancer is not the most serious type of skin cancer (that's melanoma), but it can spread if it's not treated. To learn more about melanoma see our leaflet on Skin cancer: melanoma.

Fair skin that burns easily is more likely than dark skin that tans easily to be damaged in this way. And the more sun you get, the more likely you are to get this cancer.

What are the symptoms?

The main symptom of squamous cell skin cancer is having a lump on the skin that grows and looks different from the skin around it. This type of lump:

• is usually raised

• is usually crusted

• can be sore when you touch it, and

• might bleed.

Sometimes these types of cancer grow very quickly.

Squamous cell skin cancers can vary in size from a few millimetres (slightly more than 1/16 of an inch across) to 5 centimetres (up to 2 inches across).

They can show up anywhere on your skin. But they usually show up on parts of the body that get the most sun, such as:

• the face

• lower legs, and

• forearms.

If you're worried about any unusual spots or patches on your skin, see your doctor.

If the doctor thinks you may have skin cancer, he or she may remove some or all of the spot and test it for cancer. This is called a biopsy.

Your doctor may refer you to a specialist skin doctor (called a dermatologist) or to a surgeon to have the biopsy, or for more treatment.

What treatments work?

The main treatments for squamous cell skin cancer are surgery and other treatments aimed at destroying or removing the cancer cells.

There are several possible treatments. The one your doctor recommends will depend on several things including:

• the size of the tumour

• its location on your body, and

• the specialist skills of your surgeon.

Treatments for Bowen's disease (very early skin cancer)

Bowen's disease is a very early form of skin cancer. It is usually easy to treat. It grows very slowly and is not usually serious. However, if left untreated it can develop into more serious types of skin cancer.

There are several treatments for Bowen's disease, including:

• cryotherapy. This involves a surgeon freezing away the damaged cells with liquid nitrogen

• electrodesiccation and curettage. The surgeon scrapes away the damaged skin cells and the wound is then healed using an electric current. It is usual to have three sessions of this treatment

• photodynamic therapy. The surgeon applies a substance to the area of damaged skin that makes it highly sensitive to light. When light is shone on the area, the cancer cells are killed. You may need to have this treatment two or three times, four weeks apart

• chemotherapy. Drugs that kill cancer cells are applied directly to the skin (for example, as a cream). You may be able to do this treatment yourself at home

• radiotherapy. Your doctor may suggest this if other treatments are not suitable for you. This treatment uses powerful x-rays to kill cancer cells.

All of these treatments seem to work well. But they are all likely to lead to some scarring and changes in skin colour around the affected area.

Treatments for invasive squamous cell skin cancer

Squamous cell skin cancer that has spread beyond the very top layer of skin is called invasive. The usual treatment is surgery to remove the cancer cells (the tumour).

If your tumour is small (less than 2 centimetres [4/5 of an inch] wide) and in an area that is highly visible, such as on or near your face, you may be able to have a type of surgery called Mohs micrographic surgery.

This operation allows the surgeon to remove less tissue than they usually would, which should leave a smaller scar.

For larger tumours (more than 2 centimetres wide), and for tumours in areas that are not so visible, standard surgery is recommended. If you have a large tumour you may be referred to a cancer specialist (called an oncologist) for radiotherapy. This is to kill off any cancer cells left behind after surgery.

You'll probably have radiotherapy treatments a few times a week for several weeks. Treatments usually take about 30 minutes.

You won't feel anything during this treatment, but you may get dry and red skin, a rash, and blisters. Afterwards the patch of skin that’s been treated may not be able to sweat, or it may be flaky and a different colour from the skin around it.

During the operation to remove your skin cancer, your doctor will cut out the tumour and also some of the healthy-looking skin around it. This is called taking a margin. The doctor takes away some of the skin from around the cancer to make sure that all the cancer cells are gone.

Doctors usually take out at least 4 millimetres (1/6 of an inch) of healthy tissue from around the cancer.

After your cancer is removed, your doctor will close your wound with stitches if needed. This step is usually very simple, and you'll be left with just a small scar after your stitches are gone.

If the wound is bigger, you may need to have a piece of skin taken from another part of your body stitched over it. This is called a skin graft.

Treatments for metastatic squamous cell skin cancer (cancer that has spread)

Tumours can sometimes spread to nearby nerves or to other tissues called lymph nodes. This type of tumour is called metastatic. If you have this type of squamous cell skin cancer you will be referred to an oncologist.

The usual treatment is surgery to remove the tumour and the affected lymph nodes. You will then need to have radiotherapy and perhaps chemotherapy. As with invasive tumours, you may be able to have Mohs micrographic surgery if your tumour is small or in a highly visible area.

Some people might also be able to have treatment with drugs called monoclonal antibodies. These can be helpful in people who:

• have skin cancer that comes back

• have invasive skin cancer, and

• have metastatic skin cancer than can't be cured by surgery or radiotherapy. 

Things you can do for yourself

If you have had squamous cell skin cancer, protecting your skin when you go outdoors can reduce your chance of getting it again.

This doesn't just mean using a sun block, but also:

• covering up

• staying in the shade as much as possible, and

• wearing a hat and sunglasses.

If you have had squamous cell skin cancer it is recommended that you stay out of the sun as much as possible, especially during the middle part of the day when the sun is at its strongest.

You should use a sunscreen that has a sun protection factor (or SPF) of at least 15. It’s important that you:

• apply sunscreen correctly and evenly and use plenty of it

• reapply it every 60 minutes and after you've been in water, and

• don't stay in the sun longer just because you're using sunscreen. You can still get burned.

Screening

Doctors recommend that people thought to have an increased chance of skin cancer should have a total-body skin examination every year. This is done by a doctor or skin specialist (dermatologist). People aged over 50 have an increased chance of skin cancer.

If you have had skin cancer before you should have an examination every six months. If your immune system is weakened you should be examined even more often. Finding new tumours when they are still small means that they are easier to treat.

If any of these apply to you, talk to your doctor about arranging a skin examination.

What will happen to me?

Most people are cured completely after surgery. But even though squamous cell is not the most serious type of skin cancer, it can sometimes spread to other parts of the body.

If this happens, the cancer is harder to cure. As with all cancers, the earlier your skin cancer is diagnosed and treated, the better your chance of a cure.

Squamous cell skin cancer doesn't usually come back. But if it does you will need more treatment.