Patient information from BMJ

Basal cell carcinoma

Last published:Apr 13, 2022

Basal cell carcinoma (BCC) is the most common type of skin cancer. It doesn’t usually spread to other tissues and it can usually be treated with simple surgery.

You can use our information to talk to your doctor about BCC. You should always see your doctor if you think that you have symptoms of skin cancer.

What is basal cell carcinoma?

Basal cell carcinoma, or BCC for short, is the most common type of skin cancer. It’s also less serious than some other types. It grows slowly and doesn’t usually spread to other tissues in the way that some skin cancers can.

There are many different types of skin cancer. BCC is one of the three main types you may have heard of. The other two are:

• melanoma, which is the least common of the main types of skin cancer. Melanoma can sometimes spread to other body tissues, which makes it harder to treat. When melanoma spreads like this it can sometimes be fatal.

• squamous cell carcinoma, which is less likely than melanoma to spread to other tissues and damage them. It is hardly ever fatal and is usually easy to treat.

What causes BCC?

The most common cause of skin cancer is too much exposure to ultraviolet light, usually in the form of:

• frequent sun exposure, especially if you get sunburn

• tanning beds, and

• sun lamps.

It can be hard to know how much time in the sun is too much. For example, some sun exposure is a good thing.

Sunlight is our main source of vitamin D, and moderate sun exposure helps to:

• strengthen our bones

• boost our immune systems

• lower blood pressure, and

• play a part in preventing many different health problems.

But this needs to be balanced against the chance of skin cancer. Broadly speaking, the lighter your skin, the more cautious you should be about spending time in the sun.

If you have very pale skin, just a few minutes a day in bright sun is probably enough. And everyone should take care not to burn. Sunburn increases your chances of skin cancer.

What are the symptoms?

BCC can vary in appearance. For example, it can look like:

• a clear, raised lump on the skin, a bit like a blister, sometimes with tiny 'spider' veins around the edges

• a red patch with crusting at the centre, or

• scabs and crusty patches that don’t heal.

When it’s more advanced it can cover a larger area, with a less well-defined shape. Also, if you stretch the skin under a bright light, BCC often has a 'pearl-like' appearance.

Diagnosing BCC

To properly diagnose BCC means having a test called a biopsy. This means that your doctor cuts away a small sample of the affected skin, which is then examined under a microscope.

If you need to have a larger area of tissue removed, you may need stitches to close the wound.

What treatments are available?

Surgery

The main treatment for curing BCC is surgery. There are several kinds of surgery. The main type is called curettage and electrodesiccation. Despite the complicated name this is a fairly simple procedure.

The surgeon:

• cuts away the area affected by the cancer

• uses an electrical needle to burn away any cancer cells left nearby, and finally

• stitches up the wound.

You may have a different type of surgery depending on where your cancer is.

For example, if the cancer is on your face, you may be able to have a technique that leaves much smaller scars than if you have it elsewhere on your body.

This technique is called Mohs surgery. To have this treatment you may have to travel to a specialist clinic, as it’s not available everywhere.

Non-surgical treatments

If you don’t want to have surgery, you may be able to have other treatments.

Cryotherapy

One treatment that can be useful on small cancers that are only in the surface layers of the skin is called cryotherapy or cryosurgery. This means that the cancer is destroyed by freezing it.

With this treatment:

• your doctor sprays liquid nitrogen onto the affected area

• this freezes the cancer cells, which kills them

• about an hour later, a blister will have formed. Your doctor or a nurse may need to drain fluid from this blister with a needle

• a scab will form on top of the blister. This scab usually drops off after about two weeks.

Some people need more than one session of this treatment to get rid of their cancer completely. As you can imagine, this treatment can also be painful in the short term.

Creams that destroy cancer cells

Another non-surgical treatment for BCC involves using cream to destroy the cancer cells.

If you have this treatment you will need to be monitored regularly by a skin specialist (dermatologist). For the treatment to work, you will need to apply the cream on most days for several weeks, as instructed by the dermatologist. Over time, the cream destroys the cancer cells.

Treatment with light

Some people can have a treatment called phototherapy, which uses bright light to kill cancer cells. This treatment is only useful for small areas of BCC that have not gone deep into the skin.

With this treatment:

• a special cream is applied to the affected area of skin and left for several hours

• your doctor then cleans away the cream

• the doctor then shines bright light onto the skin for about 15 minutes

• the light reacts with the cream that has been absorbed by the cancer cells, killing the cells.

BCC that has spread (metastatic BCC)

Cancer that spreads to other parts of the body is called metastatic cancer. But it is extremely rare for BCC to spread in this way. It happens to one in every few hundred people with BCC.

If it does happen, drug treatments can slow down the spread of the cancer. But they can’t stop it. When this happens, the cancer is usually fatal within a few months or years.

What to expect in the future

Basal cell carcinoma is not one of the more dangerous types of skin cancer. But you should still see a doctor if you think you might be affected by any type of skin cancer.

Surgery to remove BCC works well. But the cancer can sometimes come back. So some people need to have more treatment.

If you have had BCC once it increases your chances of having it again. So you should keep an eye on your skin, and take care not to spend too much time in the sun.

Your doctor should help you arrange regular check-ups with a dermatologist, who will know what to look out for.