What is squamous cell carcinoma?
Squamous cell carcinoma (SCC) is the second most common skin cancer of all, but squamous cells can also be found on some other parts of the body. When it presents as skin cancer it begins as a small nodule and can develop into a larger ulcer. It has the appearance of long-lasting, rough, scaly, thick patches, which can bleed if scratched, knocked or struck. They are similar to warts or open sores with raised edges and a crusty surface. People with light skin, light hair and blue or grey eyes who have had sun exposure are considerably more at risk of developing this type of cancer, however, all skin types are vulnerable. It is also more common in later life.
Symptoms of squamous cell carcinoma
Squamous cell cancers tend to appear in sun-exposed areas of the body, such as the face, ears, neck, lips, and back of the hands. They can also appear, although less frequently, on the skin of the genital area. At other times they can arise in scars or skin sores that appear in other areas of the body.
Cancers can appear in the following ways:
- Red spots that are rough or scaly and may bleed or scab over.
- Bigger growths, sometimes with a lower area in the centre.
- Open sores that do not heal or that heal and come back.
- Wart-like growths.
How is squamous cell carcinoma diagnosed?
If a patient suspects they might have skin cancer, their doctor will examine their skin and may commission tests to determine if it is cancer or another skin problem. Other tests may be done if there is a chance that the skin cancer has spread to other parts of the body.
Medical history and a physical examination: a specialist will ask the patient about their symptoms. They will want to know when the skin sore first appeared, if it has changed in size or appearance and if it has caused pain or bleeding. They may also ask if in the past the patient has been exposed to conditions that can cause skin cancer and if any members of their family have had skin cancer.
Skin biopsy: if the doctor suspects that it is skin cancer, a sample will be removed and sent to a laboratory for close analysis. If the biopsy removes the tumour entirely, this is often enough to treat early-stage squamous cell cancers without further treatment.
How is squamous cell carcinoma treated?
Many squamous cell skin cancers are detected and treated in the early stages, at which time they can be removed with local treatment methods. Generally, minor squamous cell cancers can be cured with these treatments. Other more advanced squamous cell cancers are more difficult to treat, and cancers that grow fast have a higher risk of coming back.
In some cases, squamous cell cancers can spread to the lymph nodes or to different parts of the body. In such cases, it may be necessary to administer treatments such as radiation therapy, chemotherapy or both.
There are different types of surgery to treat squamous cell skin cancers.
- Excision: The tumour is removed, along with a small margin of normal skin cells.
- Curettage and electrodessication: This method is useful in the treatment of minor squamous cell cancers, but it is not recommended for larger tumours.
- Mohs surgery: This operation is especially useful to treat squamous cell cancers more than 2cm wide or with poorly defined edges, for those cancers that have come back after treatment, for cancer that has spread throughout nerves under the skin and for localised cancer in certain areas of the face or genital area.
Sometimes radiation therapy is a good option for patients with larger tumours, specifically in areas where surgery is difficult or for patients who cannot undergo surgery. This treatment is not used as much as the initial treatment in younger patients due to the possible risk of long-term problems.
Cryosurgery is used in some early-stage squamous cell cancers, specifically in people who cannot undergo surgery, but it is not recommended for larger invasive tumours, or tumours in certain parts of the nose, ears, eyelids, scalp or legs.