What is Squamous Cell Carcinoma?
Squamous cell carcinoma (SCC) is the second most common type of skin cancer behind basal cell carcinoma. As its name suggests, it develops in the flat squamous cells that make up the outer layer of the skin (called the epidermis). Until recently, SCC was more often seen in older people, mainly men who worked outdoors. But today, more women and younger people are developing SCC, according to the College of American Pathologists.
Most squamous cell skin cancers appear on sun-exposed areas of the body – the face, neck, ears, back of the hands and scalp. But they can occur in other areas too. For example, SCCs can develop in the mouth or on the genitals. In most cases, SCCs are cured by either removing the cancerous growth and/or using medications applied to the skin. But, if it spreads, it can cause damage and scarring and may even invade nearby tissue or organs. If your cancer spreads to the bone, visit our bone metastases page.
What Can I Do to Protect Myself?
Fortunately, most SCCs are found early and can be cured. Here are some steps you can take to help protect yourself:
- Pay attention to sun safety. Avoid being in the sun during peak daylight hours, always apply (and reapply) SPF 30 or higher broad-spectrum (UVA/UVB) sunscreen, and wear protective clothing, sunglasses and wide brimmed hats. Don’t skip putting sunscreen on your lips, ears, backs of your hands, neck or the top of the scalp.
- Go to any and all follow-up appointments with your doctor. If you have had a skin cancer, you are more likely to have another. Be sure to get regular skin exams. When found early, skin cancer can be cured.
- Check your skin regularly. Watch for changes in size, color, texture and appearance. If it worries you at all, let your doctor know.
- Tell others. Talk to your family and friends about the importance of skin cancer prevention too.
Symptoms and Diagnosis
Certain people are more likely to develop squamous cell carcinoma (SCC), including:
- Having fair skin, light-colored eyes or blond or red hair
- Spending too much time in the sun (without protection) or using tanning beds
- Frequent sunburns, especially at an early age
- Having had a previous SCC, other skin cancer or certain pre-cancerous conditions such as actinic keratosis, leukoplakia and Bowen’s disease
- Old scars, burns, ulcers or chronic inflammation of the skin
- Certain viruses such as HPV (Human Papillomavirus)
- Exposure to many x-rays or chemicals
- Having had an organ transplantation and on immunosuppressive medications
What Does SCC Look Like?
A change on the skin is the most common sign of skin cancer, including SCC. That’s why it is important to get to know your skin. If you notice a new growth, a sore that isn’t healing or a change in an existing mole or other area of the skin, get it checked out.
SCCs might appear as:
- An elevated wart-like lump that is small, smooth, shiny, pale or waxy
- A flat red spot or rough patch of skin that may become itchy
- A bleeding or crusting sore that doesn’t seem to heal
- A red or brown patch that is rough and scaly
In the majority of cases, squamous cell carcinoma (SCC) is easily cured using local surgery and/or medications applied to the skin (called topical therapies).
Treatment will depend on the size, location and how deep the tumor is in the skin, as well as if it has spread elsewhere.
Treatments usually include:
There are several different types of surgical procedures that can be used:
- Excision – the entire growth is removed along with a surrounding border of normal skin
- Curettage and electrodessication – the tumor is scraped down to its base followed by pulses of electrical energy
- Mohs surgery – the goal is to remove skin cancer one layer at a time to spare healthy tissue. After each layer is removed, it is sent to an off-site laboratory to be examined, so the surgeon knows whether more layers need to be removed in real-time.
- Laser surgery – lasers can be used to kill SCCs that are very early and sit on the surface of the skin. It is often used on the lip, face or scalp.
- Cryosurgery – may be considered for patients with small, well-defined primary tumors; this involves freezing the cancer cells.
SCC can invade nearby tissue. If this happens, several surgeries may be needed to try to remove all of the cancer cells. These procedures can be disfiguring and very upsetting. If nearby lymph nodes are involved, a lymph node dissection may also be required.
Medications for the Skin
If SCC is “superficial” (in other words, not very deep in the skin), creams containing chemotherapy medications (imiquimod, 5-Fluorouracil) can be applied to the skin.
This treatment uses a medication, called a photosensitizer, and a particular type of light to kill cancer cells.
Radiation therapy uses high-energy x-rays to target and kill cancer cells. The use of radiation is controversial to treat SCC, but may be considered for patients who have:
- Undergone lymph node dissection
- Remaining SCC cells after surgery (positive margins)
- Evidence that cancer cells are spreading to the space surrounding a nerve (called perineural invasion) on a pathology report)
For SCC that has spread (metastasized), systemic therapy can be considered which includes chemotherapy, targeted therapy, and clinical trials. For organ transplant patients who have many SCCs, transplant physicians can consider adjusting the immunosuppressive treatment if appropriate.