Canadian Skin Cancer Foundation



	SQUAMOUS CELL What is Squamous Cell Carcinoma? Squamous cell carcinoma (SCC) is the second most common form of skin cancer, with over 250,000 new cases per year estimated in the United States. Squamous cells are cells that compose most of the epidermis. An abnormal growth of these cells is known as a squamous cell carcinoma. Most SCCs are not serious. When identified early and treated promptly, the future is bright. However, if overlooked, they are harder to treat and can cause disfigurement. While 96 to 97 percent of SCCs are localized, the small percentage of remaining cases can spread to other parts of the body, and the results are often fatal. Cause Like all skin cancers, chronic overexposure to the sun is the primary cause of nearly all cases of squamous cell carcinoma. Tumors appear most frequently on the face, neck, bald scalp, hands, shoulders, arms and back: all places that are exposed to the sun. The rim of the ear and the lower lip are especially vulnerable to these cancers. Squamous cell carcinomas may also occur where skin has suffered certain kinds of injury: burns, scars, long-standing sores, sites previously exposed to X-rays or certain chemicals (such as arsenic and petroleum by-products). In addition, chronic skin inflammation or medical conditions that suppress the immune system over an extended period of time may encourage development of squamous cell carcinoma. Occasionally, squamous cell carcinoma arises spontaneously on what appears to be normal, healthy, undamaged skin. Some researchers believe that a tendency to develop this cancer may be inherited. Am I at Risk Anyone with a substantial history of sun exposure can develop squamous cell carcinoma but certain environmental and genetic factors can increase the potential for this disease. Sun Exposure: Sunlight is responsible for over 90 percent of all skin cancers. Working primarily outdoors, living in an area that gets a lot of high intensity sunlight (like Australia), spending time in tanning booths all increase your exposure to UV rays and thus increase your risk for developing skin cancer, including squamous cell carcinoma. Skin Type: People who have fair skin, light hair, and blue, green, or gray eyes are at highest risk. Dark-skinned individuals of African descent are far less likely than fair-skinned individuals to develop skin cancer. Check out your skin type and how it affects your skin cancer risk. More than two thirds of the skin cancers that individuals of African descent develop are SCCs, usually arising on the sites of preexisting inflammatory skin conditions or burn injuries. Although dark-skinned individuals of any background are less likely than fair-skinned individuals to develop skin cancer, it is still essential for them to practice sun protection. Previous Skin Cancer: If you have had a skin cancer of any type, it increases your risk of developing another one. Reduced Immunity: People with weakened immune systems due to excessive unprotected sun exposure, chemotherapy, or those with certain illnesses such as HIV are more likely to develop squamous cell carcinoma. What to Look For Squamous cell tumors are thick, rough, horny and shallow when they develop. Occasionally, they will ulcerate, with a raised border and a crusted surface over a raised, pebbly, granular base. See photos below for examples. Any bump or open sore in areas of chronic inflammatory skin lesions indicates the possibility of squamous cell carcinoma, and a doctor should be consulted immediately if this is the case. Usually, the skin in these areas reveals telltale signs of sun damage, such as wrinkling, changes in pigmentation, and loss of elasticity. That is why tumors appear most frequently on sun-exposed parts of the body. Precancers and Early Cancers There are some precursor conditions, called precancers and early cancers (also called cancer in situ) that are sometimes associated with the later development of SCC. They include actinic keratosis, actinic chelitis, leukoplakia, and Bowen's disease, although most dermatologists believe that Bowen's disease is just another name for a type of superficial SCC that hasn't spread yet. It appears as a persistent, scaly red-brown, scaly patch. It may resemble eczema or psoriasis. If you notice any change on your skin — a mole changing appearance, a new growth, a sore that won't heal — have a doctor look at it without delay. Treatments for early cancers are much more effective than treatments for later ones.
copyright Christine Lycka 2007

What is Squamous Cell Carcinoma?
Squamous cell carcinoma (SCC) is the second most common form of skin cancer, with over 250,000 new cases per year estimated in the United States. Squamous cells are cells that compose most of the epidermis. An abnormal growth of these cells is known as a squamous cell carcinoma.

Most SCCs are not serious. When identified early and treated promptly, the future is bright. However, if overlooked, they are harder to treat and can cause disfigurement. While 96 to 97 percent of SCCs are localized, the small percentage of remaining cases can spread to other parts of the body, and the results are often fatal.
Cause

Like all skin cancers, chronic overexposure to the sun is the primary cause of nearly all cases of squamous cell carcinoma. Tumors appear most frequently on the face, neck, bald scalp, hands, shoulders, arms and back: all places that are exposed to the sun. The rim of the ear and the lower lip are especially vulnerable to these cancers.

Squamous cell carcinomas may also occur where skin has suffered certain kinds of injury: burns, scars, long-standing sores, sites previously exposed to X-rays or certain chemicals (such as arsenic and petroleum by-products). In addition, chronic skin inflammation or medical conditions that suppress the immune system over an extended period of time may encourage development of squamous cell carcinoma.

Occasionally, squamous cell carcinoma arises spontaneously on what appears to be normal, healthy, undamaged skin. Some researchers believe that a tendency to develop this cancer may be inherited.

Am I at Risk
Anyone with a substantial history of sun exposure can develop squamous cell carcinoma but certain environmental and genetic factors can increase the potential for this disease.

Sun Exposure:
Sunlight is responsible for over 90 percent of all skin cancers. Working primarily outdoors, living in an area that gets a lot of high intensity sunlight (like Australia), spending time in tanning booths all increase your exposure to UV rays and thus increase your risk for developing skin cancer, including squamous cell carcinoma.

Skin Type:
People who have fair skin, light hair, and blue, green, or gray eyes are at highest risk. Dark-skinned individuals of African descent are far less likely than fair-skinned individuals to develop skin cancer. Check out your skin type and how it affects your skin cancer risk.

More than two thirds of the skin cancers that individuals of African descent develop are SCCs, usually arising on the sites of preexisting inflammatory skin conditions or burn injuries. Although dark-skinned individuals of any background are less likely than fair-skinned individuals to develop skin cancer, it is still essential for them to practice sun protection.

Previous Skin Cancer:
If you have had a skin cancer of any type, it increases your risk of developing another one.

Reduced Immunity:
People with weakened immune systems due to excessive unprotected sun exposure, chemotherapy, or those with certain illnesses such as HIV are more likely to develop squamous cell carcinoma.

What to Look For
Squamous cell tumors are thick, rough, horny and shallow when they develop. Occasionally, they will ulcerate, with a raised border and a crusted surface over a raised, pebbly, granular base. See photos below for examples.

Any bump or open sore in areas of chronic inflammatory skin lesions indicates the possibility of squamous cell carcinoma, and a doctor should be consulted immediately if this is the case. Usually, the skin in these areas reveals telltale signs of sun damage, such as wrinkling, changes in pigmentation, and loss of elasticity. That is why tumors appear most frequently on sun-exposed parts of the body.

Precancers and Early Cancers
There are some precursor conditions, called precancers and early cancers (also called cancer in situ) that are sometimes associated with the later development of SCC. They include actinic keratosis, actinic chelitis, leukoplakia, and Bowen's disease, although most dermatologists believe that Bowen's disease is just another name for a type of superficial SCC that hasn't spread yet. It appears as a persistent, scaly red-brown, scaly patch. It may resemble eczema or psoriasis.

If you notice any change on your skin — a mole changing appearance, a new growth, a sore that won't heal — have a doctor look at it without delay. Treatments for early cancers are much more effective than treatments for later ones.