Squamous cells are flat, thin cells that line the surface of the skin and various tissues and organs within the body, and squamous cell carcinoma (SCC) is a form of cancer that affects these cells. When referring specifically to cancers in the epidermis or upper layers of the skin, it is specifically called cutaneous squamous cell cancer (cSCC), setting it apart from cancer that affects squamous tissues in other parts of the body.
Squamous cells can become cancerous if they begin growing uncontrollably.
SCC accounts for about 20% of non-melanoma skin cancers, with an estimated 1.8 million cases diagnosed in the United States each year. The primary risk factor for most forms of SCC is chronic exposure to UV light, either from the sun or from artificial sources like tanning beds. For that reason, it appears more frequently in those with fair skin, light hair, and blue or green eyes, as their skin has less protective melanin to resist the radiation from disrupting cellular DNA.
Precursors to & Types of Squamous Cell Carcinoma
SCC can present in various forms:
Actinic Keratosis (Pre-Cancerous Lesion)
Actinic Keratosis could indicate an early stage of SCC. It is characterized by rough, scaly patches on the skin that are pink or flesh-colored and typically less than ¼ inches across. The lesions typically appear on areas frequently exposed to the sun, such as the face, ears, back of the hands, and scalp.
Because of its association with prolonged or excessive UV radiation, the risk of developing actinic keratosis increases with age because the sun damage accumulates over time.
These patches grow slowly over time, and while they don’t typically have any symptoms, they can be sore or itchy in some cases. Actinic Keratosis will develop into squamous cell carcinoma (1 in 10), so many dermatologists recommend treatment or careful monitoring to ensure that there are no changes indicating cancerous growth.
Squamous Cell Carcinoma In Situ – Bowen Disease
At the earliest stage of SCC, when the cancerous cells are localized to the epidermis, it is called “Bowen disease” or “SCC in situ.” These pre-cancerous lesions are larger than actinic keratosis, with a red, scaly appearance that may develop a crust.
While Bowen disease is still considered pre-cancerous, treatment is still recommended to avoid the condition spreading to the tissues beyond the epidermis.
Invasive Squamous Cell Carcinoma
Invasive SCC is an advanced stage that has spread beyond the epidermis into the deeper layers of the skin or even other tissues. This type of carcinoma often appears as a thick, red, scaly patch or as a lump with a rough surface.
The risk of metastasis increases as the SCC penetrates deeper into the skin and possibly into lymph nodes or distant organs, so early removal is key to a more optimistic prognosis.
Staging Cutaneous Squamous Cell Carcinoma
Doctors use a standard “staging” list to determine the severity of skin cancer based on the size of the lesion and how far it’s spread past the epidermis.
- Stage 0: Squamous cell carcinoma in situ, so the cancerous cells are still only present in the upper skin layers. At this stage, SCC is still very treatable and has a 99% 5-year survival rate.
- Stage I: The cancer cells have spread past the epidermis but have not reached the lymph nodes or healthy tissue past the skin.
- Stage II: The lesion has not metastasized to lymph nodes but has at least one high-risk feature such as reaching the skin’s lower layers or the nerves.
- Stage III: The cancer has reached the lymph nodes but has not spread to any other organs or tissues.
- Stage IV: The SCC is now considered “invasive” and has spread to at least one distant organ, like the brain, lungs, or another area of the skin.
Treatment Options
There are several treatment options for SCC to discuss with your caregiver.
Surgical Excision
Most cases of BCC are treated with surgical excision, during which the doctor cuts out the affected tissue in addition to a certain margin of healthy skin to better ensure that each and every cancer cell is removed. This option is most often used in areas that are unlikely to redevelop cancerous growth, such as the hands or feet.
Laser Therapy
Using a beam of intense light, a doctor can directly target the cancerous cells without harming the tissues around the lesion. They may use an ablative laser, which vaporizes the tumor, or a nonablative laser, which destroys the growth using heat.
Mohs Surgery
We’ll be looking into Mohs surgery in more detail before the end of May, but the brief summary is that it involves removing cancerous skin layer by layer until, when examined under a microscope, there are no more cancerous cells. Unlike an excision, this prevents having to remove as much healthy skin and is typically performed in cases where the lesion is on the face, scalp, neck, is large, or goes deeper into the skin.
Curettage and Electrodessication
In cases of SCC In Situ/Bowen Disease, you may be eligible for a simple curettage and electrodesiccation (C&E) procedure. During this treatment, the doctor will scrape the surface layer of the cancerous growth with a curet and then use an electric current to remove the lesion.
Radiation
In cases where there is an increased risk of recurrence, radiation is sometimes used after surgery to target cancer cells with high-energy X-ray or proton beams.
Freezing
Superficial (surface-level) lesions can sometimes be removed by freezing the cancer cells with liquid nitrogen in a treatment called cryosurgery. It’s ideal for treated Actinic Keratosis and SCC In Situ/Bowen Disease, when surgery isn’t a viable option.
Chemotherapy
Once SCC has metastasized or recurs continually despite using other treatments, chemotherapy may be necessary to kill cancer cells with extremely powerful drugs.
5 Tips for Preventing Squamous Cell Carcinoma
- Always, always, always wear a broad-spectrum sunscreen with SPF 30 or higher, even if you’re not planning on spending a lot of time outside, it’s wintertime, or it’s gloomy outside. UV rays can still reach your skin, causing DNA damage that leads to cancerous growth in the basal cells. Those with fair skin should take extra precautions by wearing wide-brimmed hats, like those available from Wallaroo, sunglasses, and UV-blocking clothing to prevent sunburns. During peak sunlight hours, remain in the shade as much as possible.
- Avoid using tanning beds, as it also exposes your skin to targeted UV radiation. Consider sunless tanning options from St. Tropez to get a summer glow without risking your skin health.
- Conduct monthly skin exams to check for any atypical growths or sudden changes to your skin. If you find a suspicious spot, contact your dermatologist immediately so that they can perform an examination and biopsy.
- Eat a diet rich in antioxidants to help protect the skin from damage. Antioxidants combat free radicals and support the skin’s repair mechanisms.
- Don’t skip your annual skin exam! Actinic keratosis and other early signs of skin cancer can evolve into more serious forms of cancer, but early detection vastly improves the chances that your dermatologist can treat the lesion with outpatient surgery to remove the cancerous cells. If you don’t already have annual visits scheduled with a Board-Certified dermatologist, we encourage you to call for an appointment with Dr. Elizabeth Briden to get started this year. It’s the best way to ensure long-term skin health and the most effective squamous cell carcinoma treatment outcomes.
