Squamous Cell Carcinoma
Squamous cell skin cancer — also called cutaneous squamous cell carcinoma (cSCC) — 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).
Skin cancer can occur anywhere on the body, but it is most often found in areas exposed to sunlight, such as the face, neck, hands, and arms.
Skin cancer is almost always curable when it is found early, but it can spread to other parts of the body. Cancer cells can invade nearby healthy tissue or break away from the tumor, enter the blood or lymph vessels, and spread to other parts of the body. When this happens, it is called metastatic disease.
Known risk factors for squamous cell skin cancer include:
- Exposure to sunlight or ultraviolet radiation from tanning booths
- Frequent blistering sunburns, especially early in life
- Having a fair complexion, which includes the following:
- Fair skin that freckles and burns easily, does not tan, or tans poorly
- Blue, green, or other light-colored eyes
- Red or blond hair
- A personal history of skin cancer
- Having more than 50 moles
- Possible genetic factors (mutations in certain genes or a family history)
- History of radiation therapy, certain conditions that suppress the immune system, or exposure to high levels of arsenic
- Solid organ transplant recipients are at a very high risk of developing cSCC after transplantation. This is due to the immunosuppressive medication used. Immunosuppressive medication is a drug that suppresses the immune response of an individual.
Signs & Symptoms
As always, talk with your health care provider if you notice anything unusual on your skin, or if you have a sore or patch of skin that will not heal. Tell your doctor if you notice changes or anything unusual on your skin. Do monthly skin checks — check all the surfaces of your skin and look closely at your moles so that you can tell if they begin to change in shape, size, or color. Cutaneous squamous cell carcinoma may look like a firm red bump, a scaly red patch, an open sore, or a wart that may crust or bleed easily.
Tests that are commonly used to find skin cancer include:
- Skin exams – A dermatologist will check the skin for bumps, moles, or spots that look abnormal in color, size, shape, or texture.
- Skin biopsy – If needed, all or part of an abnormal-looking growth is cut from the skin. A pathologist will look at the sample under a microscope to check for signs of cancer. Different types of biopsies may be used depending on cancer and its location.
- Shave biopsy: A doctor uses a sterile blade to shave off a growth that looks abnormal.
- Punch biopsy: A special instrument is used to cut out circular pieces of skin or tissue.
- Incisional biopsy: The doctor removes part of a growth using a scalpel.
- Excisional biopsy: The doctor removes the entire growth or abnormal area of skin using a scalpel.
If the disease is more advanced, other diagnostic tests may be added, including CT or PET scans. However, this is done very infrequently.
Squamous cell skin cancer is often broken into the following categories:
Local: Tumors that are confined to the original site of disease. Local cSCC is usually curable.
Locally advanced: Tumors that have spread to surrounding skin or lymph nodes. Locally advanced cSCC can be curable by surgery or radiation.
Unresectable: Tumors that can no longer be cured by surgery and/or radiation. Unresectable cSCC cannot be cured but can be controlled by treatments like chemotherapy and immunotherapy.
Metastatic: Tumors that have spread beyond the original area to other parts of the body. Metastatic cSCC cannot be cured but can be controlled by treatments like chemotherapy and immunotherapy.
Local Versus Advanced cSCC
Your doctor may also use the words “local” and “advanced” to describe your cSCC. Local cSCC is treated very differently than the other categories. Most people who have cSCC have local disease. When you read about cSCC being highly curable, that is for the 95% of people who have local cSCC.
Treatment and Side Effects
The treatment for skin cancer will depend on a number of factors, including:
- The stage of the disease (whether it has spread deeper into the skin or to other areas of the body)
- The type of skin cancer
- The size and location of the tumor
- Your preferences
Treatment options for cSCC may include:
- Topical Medications
- Radiation Therapy
- Targeted Therapy
- Clinical Trials
Surgery is used to remove the cancer cells. Different surgical techniques may be recommended.
- Curettage and electrodesiccation: This procedure is also called C & E. The skin cancer cells that can be seen are scraped down to its base, then an electric needle will burn (cauterize) the bottom of the area.
- Mohs Surgery: This procedure removes the skin cancer a layer at a time. Then it is checked under the microscope to check if all the cancer was removed. The surgeon may need to remove a few layers.
- Excision: The skin cancer is removed with a scalpel (sharp surgical blade) and the skin sample is sent to the pathology lab to check if the margins are free of cancer.
Possible side effects of surgery may include pain, scarring, numbness, skin stretching, wound problems, infection, and changes in appearance where the surgery was performed.
Topical medications are applied to the skin when skin cancer is a type that is known to be very thin. Treatments may include photodynamic therapy (a light-sensitive drug is applied to the skin cancer cells), cryotherapy (a cold liquid is used to freeze the cancer cells), and topical drugs (5-fluorouracil also known as 5-FU).
Possible side effects for topical medications include pain, itching, burning, irritation, inflammation, dryness, swelling, and tenderness at the site of application.
Cryotherapy is a procedure in which an extremely cold liquid is used to freeze and kill abnormal cells. The cold liquid is called liquid nitrogen, liquid nitrous oxide, or compressed argon gas.
Radiation therapy is the use of high-energy rays to kill or damage cancer cells. It is given before, during, or after other treatments. The goal is to damage as many cancer cells as possible without harming healthy tissue. To lessen the damage, doses are given in very precisely mapped areas.
Common side effects include nausea, fatigue, and skin changes like redness, dryness, or itching at the site of treatment. Other side effects are specific to the part of the body being treated. Side effects can last after treatment is done.
Radiation is most often used in patients who cannot undergo surgery or it sometimes may be used after a patient has had surgery. It may also be used in patients who have cSCC that has spread to lymph nodes.
Chemotherapy involves the use of drugs to destroy cancer cells. It is a systemic (whole-body) treatment. This means it can destroy cancer cells almost anywhere in your body. It may be given by IV (through a vein), in pill form (by mouth), as an injection (a shot), applied directly on the skin into the area around the tumor, or placed directly into the tumor site. Most often, chemo is given in an outpatient clinic. You will have a regular schedule of treatments for a set period of time.
Chemotherapy is most effective against fast-growing cells, like cancer. But some healthy, normal cells may also be damaged by this treatment. The side effects will vary depending on the drug(s) you take, the dose of your drugs, and how often you get treatments. Common side effects include mouth sores, fatigue, hair loss, nausea, “chemo brain,” and low blood cell or platelet counts. Chemotherapy may not be appropriate for all patients.
Immunotherapy uses the body’s natural defenses (the immune system) to find, attack, and kill cancer cells. The immune system’s job is to attack any cell that it sees as unhealthy or abnormal. Cancer cells can hide from these defenses or even stop an attack. Most immunotherapy is given by IV (through a vein). You may get treatment in a doctor’s office, in a clinic, or as an outpatient. It is important to review that immunotherapies may not be a good option for those on immunosuppressive medications.
Targeted therapy aims to more precisely attack cancer cells. These drugs target changes in the genes or proteins of cancer cells that help them grow, divide, and spread. They treat the cancer cells with less harm to normal cells. There are different types of targeted therapy. Targeted therapy is being studied for this type of cancer. Currently available targeted therapy cSCC may be given as an IV (through a vein). Ask if it is an option for you.
Common side effects include skin problems (rash, dry skin, itching), fatigue, or a flu-like reaction with fever, chills, and diarrhea.
Be sure to ask about clinical trials. Clinical trials are research studies to test new treatments or learn how to use current treatments better. Today’s standard drugs were once in clinical trials. Tomorrow’s drugs are in them today.
In some cases, the treatments with the best chance of success may be available only through clinical trials. Trials are offered for many cancers, at many different stages. Everyone is not eligible for every trial. If you have cancer that has come back or spread, it is especially important to ask about clinical trials.
Because skin cancer can come back, be sure to ask your doctor how often to have your skin checked for signs of cancer. Remember to keep any follow-up visits.
Spotlight on Skin Cancer: Advanced SCC and BSSC Skin Cancers
In this episode of our special series Spotlight on Skin Cancer, we take a look at 2 forms of advanced skin cancer: advanced basal and squamous cell skin cancers.
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