Squamous cell carcinoma is a common form of skin cancer that originates in the squamous cells that make up the middle and outer layers of the skin. They account for 2 out of 10 cases of skin cancer and usually appear on sun-exposed areas of the skin.
Squamous cell carcinoma of the skin
The vast majority of squamous cell carcinomas are the result of prolonged exposure to UV radiation from the sun or tanning lamps. This UV radiation can cause alterations in DNA and turn a normal cell into a cancerous one.
Factors that can increase the risk are:
- Fair skin. Although anyone can develop this type of cancer, having less melanin in the skin provides less protection against the harmful effects of UV rays.
- Excessive sun exposure. Spending a lot of time in the sun without adequate protection significantly increases the risk.
- Use of tanning beds.
- History of sunburns.
- Personal history of precancerous lesions or skin cancer.
- Weakened immune system, such as people with leukemia or those on immunosuppressive treatment.
- Smoking.
- Having certain conditions like xeroderma pigmentosum.
Symptoms
Squamous cell carcinoma can occur anywhere on the body, although it is much more common in sun-exposed areas such as the scalp, ears, or face. Signs and symptoms include:
- A rough, scaly red bump or patch
- Open sores that do not heal, or that heal and return
- An elevated area on a scar or old sore
They can also present as a flat area that shows slight changes compared to normal skin.
Prevention
The majority of skin carcinomas can be prevented. It is recommended to:
- Avoid sun exposure during the central hours of the day, when UV rays are strongest.
- Use broad-spectrum sunscreen year-round, even on cloudy days.
- Wear sun-protective clothing when sun exposure is unavoidable.
- Avoid tanning beds.
- Regularly check your skin and attend dermatological check-ups to examine moles, freckles, etc.
- Do not smoke.
13.5 million variants
18 loci
Bibliography
Sarin KY, Lin Y, Daneshjou R, et al. Genome-wide meta-analysis identifies eight new susceptibility loci for cutaneous squamous cell carcinoma. Nature Communications. 2020 Feb;11(1):820.
Waldman A, Schmults C. Hematol Oncol Clin North Am. 2019 Feb;33(1):1-12.
Squamous cell carcinoma of the skin. Mayo Clinic [Aug 2023]
Basal and Squamous Cell Skin Cancer. American Cancer Society [July 2019]