Squamous cell carcinoma is the second most common skin cancer in the United States. More than 700,000 cases of squamous cell carcinoma (SCC) are diagnosed every year.
The risk of developing a squamous cell carcinoma depends on the amount of accumulated sun damage and weaknesses in the immune system. Solid-organ transplant recipients, whose immune systems are suppressed to protect the transplant are 65-250 times more likely to develop SCC than the general population.
Squamous cell carcinoma (SCC) originates in the spinous layer, which makes up most of the epidermis. SCC is more rapidly growing and aggressive than basal cell carcinoma and can spread to distant sites of the body in up to 4% of patients. Early diagnosis and proper treatment can prevent this.
The risk of metastasis (distant spread) of SCC depends on:
Size of the tumor
Thickness of the tumor
Location on the ear or lip
Most squamous cell carcinomas arise from a precancerous lesion, known as an actinic keratosis, a small scaly papule or patch that feels like sandpaper when touched. Actinic (meaning from the sun) keratoses normally occur on sun-exposed skin. Thickening or hardening of the keratosis may signal progression to a squamous cell carcinoma.
SCCs can occur anywhere on the body including mucous membranes and genitals, but are most common in sun-exposed areas, like the head and neck, the ear rim, lower lip, arms and legs. Because hands are chronically exposed to UV light, they are a particularly common area of actinic keratoses and squamous cell carcinoma.
Who gets squamous cell carcinomas?
The likelihood of developing SCC increases when you have one or more of the following risk factors:
Men are at least twice as likely to develop SCC as women
History of extensive sun exposure
History of indoor tanning
Presence of actinic keratoses
Personal or family history of skin cancer
Older people are more likely to develop SCC, most likely due to total amount of previous sun exposure.
SCC can occur in darker skin types as well.
The majority of skin cancers in African Americans are squamous cell carcinomas, usually arising in pre-existing ulcers, burn scars or sites of chronic skin inflammation.
History of radiation therapy
History of exposure to arsenic or coal tar
Presence of long-standing areas of skin inflammation, ulcers or burn scars
Human papilloma virus (HPV) infection
Many genital tumors are related to infections with HPV, particularly types 16 and 18.
Verrucous carcinoma, a type of SCC that clinically has a warty appearance, is related to more common HPV subtypes 6 and 11. Verrucous carcinoma occurs on the hands, feet and genitals.
Rare genetic disorders, like xeroderma pigmentosum
What causes squamous cell carcinoma?
Ultraviolet light exposure is the major cause of squamous cell carcinoma. Both the sun and indoor tanning beds are sources of ultraviolet light.
Patients with rare genetic disorders, like xeroderma pigmentosum are exquisitely sensitive to UV light and are much more likely to develop SCC than the general population.
Other causes include exposure to certain chemicals, radiation therapy, immunosuppression and long-standing ulcers or burn scars.
What does squamous cell carcinoma look like?
SCC looks like a red, crusted or scaly patch, a hard, red papule or a non-healing ulcer. Because it commonly arises from actinic keratoses, there may be numerous actinic keratoses in the surrounding area. SCC can also look like a cup-shaped or a crater-shaped red nodule.
Since it is sometimes difficult to differentiate SCC from other skin disorders, a thorough skin examination by a dermatologist is needed once a year, or more often if you have many risk factors for developing skin cancer.
Some photos courtesy of the Global Skin Atlas
How is squamous cell carcinoma diagnosed?
A biopsy is required for the diagnosis of skin cancer. A biopsy is performed by numbing the area of the skin suspected of being cancerous with a local anesthetic injection and removing the lesion or a portion of it. The pathologist examines the tissue specimen to determine if there is skin cancer.
Treatments for squamous cell carcinoma
Treatment for SCC depends on the type, size and location of the tumor.
Treatment methods used for BCC:
Mohs micrographic surgery
Imiquimod topical cream
Prevention of squamous cell carcinoma
Avoid sun exposure between the hours of 10 am and 4 pm
Use a broad-spectrum sunscreen with excellent UVB and UVA coverage.
Apply the sunscreen at least 20 minutes before going outside
Reapply sunscreen every two hours or more often if swimming or sweating
Wear sun-protective clothing, a wide-brimmed hat and sunglasses
Summit Medical Group is proud to provide medical, surgical and cosmetic dermatology services to women and men in the Tri-State Area, New York and New Jersey, including the following counties and cities: Essex County, Morris County, Bergen County, Union County, Passaic County, Somerset County and Sussex County, NJ - Livingston, Millburn, Short Hills, West Orange, Berkley Heights, Caldwell, Cedar Grove, Cedar Knolls, Chatham, East Hanover, Englewood Cliffs, Essex Fells, Fair Lawn, Florham Park, Fort Lee, Glen Ridge, Jersey City, Kinnelon, Madison, Maplewood, Mendham, Montclair, Montvale, Morristown, New Providence, North Caldwell, Parsippany, Randolph, Roseland, South Orange, Springfield, Summit, Union, Verona, West Caldwell, Whippany and Westfield, NJ.
Disclaimer: The information on this Web site is solely for to educate patients. It is not intended to be medical advice and, therefore, should not be considered a substitute for consultation with a qualified medical professional. Communications to or from the Summit Medical Group Web site and any person will not be used to establish a relationship between a patient and doctor.