Squamous cell carcinoma is a type of skin cancer caused by an overproduction of squamous cells in your epidermis, the top layer of your skin. Exposing your skin to the sun’s UV rays puts you at a high risk of getting skin cancer. Treatment to remove cancer leads to a positive prognosis if the cancer is found and treated early.
Squamous cell carcinoma (SCC) or cutaneous squamous cell carcinoma (CSCC) is the second most common form of skin cancer after basal cell carcinoma. It starts in squamous cells in the outer layer of your skin, the epidermis. Usually, squamous cell carcinomas form on areas of your skin that receive the most sun exposure like your head, arms and legs. Cancer can also form in areas of your body where you have mucous membranes, which are the inner lining of your organs and body cavities like in your mouth, lungs and anus.
There are different types of squamous cell carcinoma based on where and how much cancer is in your body:
Squamous cell carcinoma can affect anyone. You’re most at risk if you:
People assigned male at birth (AMAB) are about two times more likely to develop squamous cell carcinoma. People over the age of 50 are most likely to get SCCs, but the incidence has been rising in people younger than 50.
Over 1 million people receive a squamous cell carcinoma diagnosis in the U.S. each year. The rate of SCC has risen about 200% over the past 30 years.
Symptoms of squamous cell carcinoma include skin changes like:
There are cancerous bumps, marks or lesions that form on your skin that can be a sign of squamous cell carcinoma, including:
You can have squamous cell carcinoma on any part of your body, but it’s most common on your:
A mutation to the p53 gene causes squamous cell carcinoma. The most common way that your p53 gene mutates is from ultraviolet (UV) exposure from the sun, or from using indoor tanning beds.
The p53 gene provides instructions for your cells to divide and replicate to replace cells when they reach the end of their lifespan. Your p53 gene is a tumor suppressor, which means that the gene controls how much and how often your cells should create new cells. Too many cells create tumors, which can be cancerous.
A mutation to the p53 gene means that your cells don’t have the instructions they need to do their job correctly. As a result, your squamous cells divide and replicate too often, causing tumors (bumps, lumps or lesions) to form in and on your body.
Cutaneous squamous cell carcinoma rarely spreads to other parts of your body (metastasize). If this does happen, it occurs slowly and can be life-threatening if left untreated. If you notice changes to your skin, contact your healthcare provider immediately.
Your healthcare provider will physically examine the area of your body where you have symptoms, looking specifically at the size, shape and location of the lump or lesion. Your healthcare provider will also ask questions to learn more about your medical history and your symptoms, which could include:
After your physical exam, your healthcare provider might offer tests to confirm a diagnosis, which could include:
Your healthcare provider will assign a stage to your diagnosis to identify how much cancer is in your body. Stages help them choose the treatment that’s right for you. There are five stages of squamous cell carcinoma:
Treatment for squamous cell carcinoma focuses on removing cancer from your body. Your treatment options vary based on the size, shape and location of your cancer and could include:
If you have invasive squamous cell carcinoma or if treatment to remove your cancer surgically isn’t right for you, your healthcare provider could offer medicine to treat your diagnosis. Medicines could include:
The most common side effect of squamous cell carcinoma treatment is cosmetic changes to your skin, like scarring, after your healthcare provider removes the cancer from your body.
If you take immunotherapy drugs to treat your cancer, talk to your healthcare provider about the side effects of the drugs.
The amount of time your body needs to heal after treatment varies for each person. The size shape and location also affect your healing time after treatment. On average, most people will recover within two to four weeks after treatment to remove cancer from their body. Your healthcare provider will meet with you a few weeks after treatment to make sure your body is healing properly and to make sure treatment was successful at removing cancer.
While you can’t prevent all types of squamous cell carcinoma, you can take steps to reduce your risk by:
If you notice changes to your skin, contact your healthcare provider or visit a dermatologist for a professional skin exam.
Most cases of squamous cell carcinoma have a positive prognosis and an excellent survival rate if you receive an early diagnosis. Early detection and treatment prevent the tumor from growing and damaging other parts of your body.
If your healthcare provider removes your cancer, there’s a chance it can return in the future. Make sure to follow up with your healthcare provider to verify you’re cancer-free. It’s also important to protect your skin from UV rays when outdoors.
Contact your healthcare provider if:
Both squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are types of skin cancer that you can get from too much sun (ultraviolet ray) exposure. An overproduction of either squamous or basal cells causes both conditions. Squamous cell carcinomas can form on your skin (epidermis) in the same way BCC does, but SCC can also form where you have mucus membranes on your body, which includes the inside of your mouth, throat, lungs and genitals.
Squamous cell carcinoma in situ is also known as Bowen disease. The term “in situ” means that the cancer cells are only in the top layer of your skin (epidermis). The most common places to find Bowen disease is on sun-exposed areas of your skin, but the condition can also appear on the skin near your anal cavity and genitals, like on your labia or vulva (vulvar cancer).
A note from Cleveland Clinic
It can be scary finding a new lump on your skin that leads to a cancer diagnosis. But treatment for squamous cell carcinoma is effective at removing cancer from your body. Take steps to prevent squamous cell carcinoma by protecting yourself from the sun’s UV rays. Call your healthcare provider if you find any new lumps or bumps on your skin, and get them examined and treated immediately.
Last reviewed by a Cleveland Clinic medical professional on 04/15/2022.
Learn more about our editorial process.