What is squamous cell carcinoma (SCC)?
SCC, or cutaneous squamous cell carcinoma (CSCC), is the second most common form of skin cancer. It starts in cells of the outer layer of the skin, the epidermis. Usually SCCs are found on the parts of skin that are most often exposed to the sun. This means hands, face, arms, legs, ears, mouths, and even bald spots on the top of the head. SCCs can also form in areas such as mucus membranes and genitals.
How common is squamous cell carcinoma (SCC)?
Over 1 million people are diagnosed with SCC in the US each year. The incidence of SCC has risen about 200 percent over the past 30 years. There are more than 15,000 deaths each year in the US from SCC. Excluding head and neck (or mucosal) SCC and CSCC in situ, about 200,000-400,000 new cases of SCC are diagnosed in the US every year, resulting in about 3,000 deaths.
Men are about two times more likely than women to develop SCCs. People over the age of 50 are most likely to get SCCs, but the incidence has been rising in younger people.
Symptoms and Causes
What causes squamous cell carcinoma (SCC)?
Repeated exposure to ultraviolet light, either from the sun or from tanning beds, is the main cause of SCC. Indoor tanning is linked to about 168,000 cases of SCC in the US each year.
People with light skin, light hair (blond or red), and light eyes (blue, green, or gray) have a higher risk of skin cancer in general, as well as SCCs. However, most of the skin cancers that develop in African Americans are SCCs.
Other risk factors include:
- Having an impaired immune system, including:
- Having an organ transplant: People who have received organ transplants are about 100 times more likely to get an SCC than the general population.
- Having skin injuries such as burns, scars, ulcers, and skin areas that were previously exposed to chemicals or X-rays.
- Having the genetic disease called xeroderma pigmentosum which means that you need to avoid the sun because your skin cannot repair itself.
- Having long-lasting and repeated infections and inflammations of the skin.
- Having a job or hobby that means that you are outside for long periods of time.
What are the signs and symptoms of squamous cell carcinoma (SCC)?
SCC signs and symptoms include skin changes like:
- A rough-feeling bump or growth which might then crust over and bleed.
- A growth that is higher than the skin but has a depression in the middle.
- A sore that will not heal, or a sore that heals and then comes back.
- A piece of skin that is flat, is scaly and red.
- A precancerous growth called actinic keratosis, which is a bump or lump that can feel dry, itchy, scaly, or be discolored.
- A precancerous skin lesion called actinic cheilitis, which happens mainly on the lower lip. The tissue becomes pale, dry, and cracked.
- A precancerous condition called leukoplakia, in which white spots develop in the mouth, on the tongue, gums, or cheeks
Diagnosis and Tests
How will your doctor diagnose squamous cell carcinoma (SCC)?
Your doctor will first examine the area in question, looking for things such as: the size, whether or not the borders are clearly or poorly defined, and location, including whether or not the spot is situated on top of a previous injury. The next step is a biopsy, which is the removal of tissue for examination under a microscope. If a tumor is considered to be high-risk, your doctor might order imaging scans to determine if nearby lymph nodes are involved or if the tumor has invaded other tissue in the area.
Management and Treatment
What are the treatments for squamous cell carcinoma (SCC)?
Your doctor will help you to decide on the best type of treatment. Factors in the decision include your overall health and age, the location of the cancer, and how invasive the cancer is.
Treatment options include:
- Scratching off with a curette, an instrument that may end in a ring or a spoon, and then burning with a special electric needle. This method is called electrodessication and curettage.
- Surgical removal:
- Mohs surgery: This is a specialized technique. The doctor first removes the visible cancer and then begins cutting around the edges. The tissues are examined during the surgery until no more cancer cells are found in tissues around the wound. If necessary, a skin graft or flap might be applied to help the wound heal.
- Excisional surgery: The growth and a bit of surrounding skin is removed with a scalpel.
- Freezing (cryotherapy or cryosurgery).
- Applying chemotherapy medication to the skin.
- Using lasers.
- Using blue light and a light-sensitive agent applied to the skin (photodynamic therapy or PDT).
- Using radiation (rare for the primary treatment of CSCC).
If you have some type of advanced or very invasive SCC, you might find that it returns or metastasizes (moves to another location of the body). There are several medications which have been approved to treat locally advanced cancers that cannot be simply treated or those that have spread to other areas of the body.
What are the complications/side effects of the treatments of squamous cell carcinoma (SCC)?
Most of the complications related to SCC treatments are cosmetic, such as scarring or redness.
How can you prevent squamous cell carcinoma (SCC)?
Practicing sun safety is the best way to prevent SCC and other skin cancers. Here are some tips:
- Avoid being in the sun from 10 am to 4 pm.
- Avoid tanning beds.
- Use a broad spectrum sunscreen with an SPF of 15 or higher each day. If you will be outside for longer periods of time, use a broad spectrum sunscreen that is water-resistant and has an SPF of 30 or higher. Put the sunscreen on 30 minutes before going outside. Put sunscreen on again every two hours, or more frequently if you have been swimming or sweating a lot.
- Use protective clothing that has built-in sun protection, which is measured in UPF. Also, use broad-brimmed hats and sunglasses.
- Do your own skin self-exam about once per month, and see a dermatologist about one time per year for a professional skin exam.
- Have any skin changes examined as soon as possible by a healthcare provider.
Outlook / Prognosis
What is the prognosis/outlook for patients who have squamous cell carcinoma (SCC)?
When SCC is found and treated early, the outlook is very good. However, it is important to find these early because larger tumors can cause more damage and can spread.
When should I call the doctor about squamous cell carcinoma (SCC)?
If you have never had skin cancer or if you have had SCC, contact your doctor if:
- You have any skin changes that cause you worry, including a new lump, mole, or sore that does not heal, or changes in a mole or spot you have had for some time.
- You need to schedule your yearly skin check appointment.
- You have any issues related to your treatment for SCC that worry you, such as excessive pain, bleeding or itching.
Are there resources for people with squamous cell carcinoma (SCC)?
You might find these organizations to be helpful.
- American Cancer Society
- Cancer Financial Assistance Coalition
- Cancer Care Inc.
- Cancer Hope Network (previously known as CHEMOCare)