Squamous cell carcinoma of the skin is a type of non-melanoma skin cancer that develops in the squamous cells (keratinocytes) that make up the outer layer of the skin.
Squamous cell carcinoma (SCC) of the skin is usually not life-threatening, though it can be aggressive in some cases. Untreated, squamous cell carcinoma of the skin can grow large or spread to other parts of your body, causing serious complications.
Most squamous cell carcinomas of the skin result from prolonged exposure to ultraviolet (UV) radiation, either from sunlight or from tanning beds or lamps. Avoiding UV light helps reduce your risk of squamous cell carcinoma of the skin and other forms of skin cancer.
Squamous cell carcinoma of the skin often occurs on sun-exposed skin, such as the scalp, backs of hands, ears or lips. But squamous cell carcinoma of the skin can occur anywhere on your body.
Signs and symptoms of squamous cell carcinoma of the skin include:
- A firm, red nodule
- A flat sore with a scaly crust
- A new sore or raised area on an old scar or ulcer
- A rough, scaly patch on your lip that may evolve to an open sore
- A red sore or rough patch inside your mouth
- A red, raised patch or wart- like sore on the skin or in the anal or genital area
Make an appointment with your dermatologist if you have a sore scab that doesn’t heal or any lesion which is changing or growing.
Squamous cell carcinoma of the skin occurs when the flat, thin squamous cells in the outer layer of your skin develop errors in their DNA. Ordinarily, new cells push older cells toward your skin’s surface, and the older cells die and are sloughed off. DNA errors disrupt this orderly pattern, causing cells to grow out of control, with squamous cell carcinoma of the skin as the result.
Ultraviolet light and other potential causes
Much of the damage to DNA in skin cells results from ultraviolet (UV) radiation found in sunlight and in commercial tanning lamps and tanning beds.
But sun exposure doesn’t explain skin cancers that develop on skin not ordinarily exposed to sunlight. This indicates that other factors may contribute to your risk of skin cancer, such as being exposed to toxic substances (e.g. cigarettes) or having a condition that weakens your immune system.
Factors that may increase your risk of squamous cell carcinoma of the skin include:
- Fair skin. Anyone, regardless of skin colour, can get squamous cell carcinoma of the skin. However, having less pigment (melanin) in your skin provides less protection from damaging UV radiation. If you have blond or red hair and light-coloured eyes and you freckle or sunburn easily, you’re much more likely to develop skin cancer than a person with darker skin.
- Excessive sun exposure. Being exposed to UV light from the sun increases your risk of squamous cell carcinoma of the skin. Spending lots of time in the sun — particularly if you don’t cover your skin with clothing or sunblock — increases your risk of squamous cell carcinoma of the skin even more.
- Use of tanning beds. People who use indoor tanning beds have an increased risk of squamous cell carcinoma of the skin.
- A history of sunburns. Having had one or more blistering sunburns as a child or teenager increases your risk of developing squamous cell carcinoma of the skin as an adult. Sunburns in adulthood also are a risk factor.
- A personal history of precancerous skin lesions. Having a precancerous skin lesion, such as actinic keratosis or Bowen’s disease, increases your risk of squamous cell carcinoma of the skin.
- A personal history of skin cancer. If you’ve had squamous cell carcinoma of the skin once, you’re much more likely to develop it again.
- Weakened immune system. People with weakened immune systems have an increased risk of skin cancer. This includes people who have leukemia or lymphoma and those who take medications that suppress the immune system, such as those who have undergone organ transplants.
- Rare genetic disorder. Some genetic conditions, such as xeroderma pigmentosum, cause an extreme sensitivity to sunlight and have a greatly increased risk of developing skin cancer.
Treatment of Squamous Cell Carcinoma
Untreated, squamous cell carcinoma of the skin can spread to the lymph nodes or other organs, and may be fatal, although this is uncommon.
The risk of aggressive squamous cell carcinoma of the skin may be increased in cases where the cancer:
- Is particularly large or deep
- Involves the mucous membranes, such as the lips
- Occurs in a person with a weakened immune system, such as someone who takes anti-rejection medications after an organ transplant or someone who has chronic leukemia
At Belfast Skin Clinic our team of Consultant Dermatlogists assess patients on an individual basis and only upon full assessment will the appropriate treatment pathway be advised. We work closely with our team of plastic surgeons to ensure a seamless care pathway for our patients.
Surgery is recommended for the removal of squamous cell carcinoma. This can usually be done under local anaesthetic and allows the patient to leave the clinic on the same day as their treatment, returning several weeks later for review and wound check with their Consultant
Rarely excision under general anaesthetic or treatment with radiotherapy is required.
If further treatment is required, this would be detailed at the review appointment.