Squamous cells make up the outermost layer of the skin, as well as some other areas of the body. They’re also found in the inner lining of hollow organs, like the throat and digestive track. This page covers squamous cell carcinoma of the skin only.
Each year, about 1 million people in the United States are diagnosed with squamous cell carcinoma of the skin. According to the American Cancer Society, each year about 2,000 people in the U.S. die of squamous cell carcinoma of the skin and basal cell carcinoma (the most common skin cancer) combined, making the disease very treatable and curable.
Squamous cell carcinoma is usually caused by prolonged exposure to ultraviolet (UV) light that builds up over the patient’s lifetime. This UV light can come from sunlight or from tanning beds. Other risk factors include chronic skin wounds and radiation therapy treatment for another cancer. These tumors usually form in the radiation site.
Organ transplant recipients also have a much higher risk of developing squamous cell carcinoma than the general population. Doctors believe immunosuppressive drugs that prevent the body from rejecting the transplanted organ makes the patient more susceptible to this type of cancer.
Squamous cell carcinoma of the skin may develop from or be associated with actinic keratoses. These are scaly, damaged patches of skin often found on areas of the body that get lots of sun exposure, like the face, scalp and back of the hands.
Overall, squamous cell carcinoma of the skin spreads, or metastasizes, only 5% of the time. Larger tumors, though, have a higher risk of metastasis. Tumors around the head and neck, including the ears, eyelid and lips, are also more likely to spread.
The symptoms of squamous cell carcinoma of the skin include sore that won’t heal and skin changes, including a lump that differs from nearby skin in color or texture.
The primary treatment for squamous cell carcinoma of the skin is surgery. Patient may also be treated with topical chemotherapy as well cryotherapy, which involves killing cancer cells with extreme cold. Clinical trials may be an option for patients whose disease has spread.
Learn more about skin cancer: