This information is about a skin condition called Bowen’s disease. In a small number of people, Bowen’s disease which has not been treated may develop into a skin cancer called squamous cell cancer (SCC).

Bowen’s disease looks like a red scaly patch on the skin. It is caused by abnormal cells growing in the outer layer of the skin (epidermis). These cells do not spread into the deeper layers of the skin. In other words they are not invasive or malignant (cancer). Bowen’s disease is sometimes called carcinoma in-situ. It is usually thought of as a condition that may develop into a cancer (precancerous).

Untreated cases of Bowen’s disease may develop into squamous cell cancer (SCC) in a small number of people (about three to five out of every 100 who have it). This is a common, curable type of skin cancer which affects the outermost cells of the skin but can spread to deeper layers of skin. If left untreated for a long time, squamous cell cancer can spread to other parts of the body.

Bowen’s disease is more common in women and it usually affects people in their 60s and 70s.

In many cases the cause is unknown. Long-term overexposure to the sun is probably the most important risk factor for Bowen’s disease. But it can occur in areas that haven’t been exposed to the sun so this isn’t the only cause.

Previous radiotherapy (for a different cancer) in the affected area is another risk factor, as is exposure to a chemical called arsenic, although this is rare. People who have to take drugs which lower their immunity (for example after a kidney transplant) are at more risk of getting Bowen’s disease.

Occasionally, Bowen’s disease can affect the genital area. This is usually linked with a common type of virus called the human papilloma virus (HPV). There are different types of this virus and some are linked with cancers, such as cervical cancer.

Bowen’s disease can grow anywhere on the body but is usually found on the lower legs. To begin with, it often looks like a red, scaly patch or sometimes like raised spots or warts. The affected skin may become itchy, sore and bleed.

Bowen’s disease is diagnosed by taking a sample of skin (biopsy). You will usually be referred to a dermatologist (specialist in skin diseases) to have this done. A local anaesthetic is given to numb the area and a small part of the affected skin is removed.

The sample is then sent to the laboratory to be looked at under a microscope.

There are a number of different treatments available for Bowen’s disease. Your treatment will depend on where it is on your body, the size, thickness and the number of patches.

How well the skin is likely to heal afterwards is an important factor when making decisions about treatment. The skin on the lower legs tends to be more fragile (especially in older people) and, as a result, there may be problems with it healing.

Observation

Bowen’s disease often grows very slowly (over a period of months or years). So, if you have a thin patch of affected skin, which is not changing, then keeping a close eye on it (observation) may be all that your dermatologist advises. You may have regular check-ups to monitor it carefully. This can sometimes be a good option for people who are more likely to have problems with skin healing after treatment.

Surgery

Surgery may be used for small areas of Bowen’s disease that can be removed under local anaesthetic. But it’s not always the best option for large patches of Bowen’s disease.

Curettage and electrocautery

Scraping away the affected area (curettage) and using heat or electricity to stop any bleeding (electrocautery) are suitable for small patches of Bowen’s disease. A local anaesthetic is given before the doctor scrapes away the area using a spoon-shaped instrument called a curette. An electrically-heated loop or needle is then applied to stop the bleeding from the wound (cauterise it) and destroy any remaining abnormal cells. After this treatment, a scar that is different from your normal skin colour may develop.

Creams (topical therapy)

A chemotherapy (anti-cancer treatment) cream called 5-fluorouracil (Efudix®), which is also known as 5FU, may be used. The cream is applied to the skin regularly over a period of time. It can make the skin in the area red and inflamed before the Bowen’s disease gets better. Usually there are no other side effects.

A newer cream called Imiquimod (Aldara®), which works by using the immune system to attack the abnormal cells, can also be used. You will be asked to apply it regularly over a period of time. It will cause some redness and skin irritation before the Bowen’s disease improves.

Photodynamic therapy (PDT)

Photodynamic therapy is a newer treatment which is used for different conditions. It can be a useful option for people with large areas of Bowen’s disease.

It uses laser, or other light sources, combined with a light-sensitive drug (sometimes called a photosensitising agent) to destroy abnormal cells. A photosensitising cream is applied to the affected area. This is usually done 4–6 hours before treatment with the light – which lasts about 20–45 minutes. Afterwards a dressing is put on to cover the area and protect it from light. Usually more than one treatment is needed.

Radiotherapy

Radiotherapy treats Bowen’s disease by using high-energy x-rays to destroy the abnormal cells while doing as little harm as possible to normal cells. Because of problems with healing, radiotherapy isn’t usually used to treat Bowen’s disease of the lower leg.

Cryotherapy

It may be possible to treat the area by freezing it. This is called cryotherapy or cryosurgery. Liquid nitrogen is sprayed onto the affected area to freeze it. At the time this feels very cold and a bit uncomfortable. Afterwards, you will have a scab, which usually falls off within a few weeks. This removes the affected skin.

Other treatments

Other treatments that can occasionally be used are Moh’s micrographic surgery or laser (using intense light energy to remove tissue).

In Moh’s surgery, the tumour is removed piece by piece and examined under a microscope straight away. Skin tissue is gradually removed until there are no signs of cancer cells.

Moh’s surgery has been recommended for Bowen’s disease in places where it’s important to remove as little healthy skin as possible. This includes the finger, lips and eyelids. It also includes Bowen’s disease affecting the genitals. Bowen’s disease of the penis is sometimes called erythroplasia of Queyrat.

A laser may also sometimes be used to treat Bowen’s disease of the finger or of the genitals. Doctors are carrying out research trials to find out how effective this treatment is in the long term.

You may have regular check-ups after treatment. At follow-up appointments, the doctors will check for any further changes that may need to be treated. But if, in between appointments, you notice changes in a patch, or a new patch developing, contact your doctor or nurse for advice.

If you aren’t being seen regularly by a skin specialist, it’s important to keep a close eye on your own skin. Let your GP know if you develop new patches or have any other skin symptoms. Many people with Bowen’s disease are looked after by their GPs when their treatment is over.

Protecting yourself from the sun is even more important when you’ve had Bowen’s disease. This means wearing clothing that protects you from the sun and using a high-factor sunscreen (SPF 30 or above).

You may have many different emotions, including anxiety and uncertainty. These are all normal reactions people go through in trying to come to terms with their condition. You may have concerns about what the best treatment is for you. It is important to discuss these concerns with the doctors and nurses caring for you.

This section has been compiled using information from a number of reliable sources, including:

• Guidelines for management of Bowen’s disease. NH Cox et al. British Journal of Dermatology. 2006.
• Photodynamic Therapy for Non-Melanoma Skin Tumours (Including Premalignant and Primary Non-Metastatic Skin Lesions). National Institute for Health and Clinical Excellence (NICE). February 2006.
• Management of Bowen’s disease of the skin. Drug and Therapeutics Bulletin. February 2004.
• Fast Facts – Skin Cancer. K Agnew et al. Health Press. Oxford 2005.

For further references, please see the general bibliography.