Skin Cancer

Skin Cancer

Skin cancer is the most common form of cancer in the U.S.

1 in 5 Americans will develop skin cancer over their lifetime

Each year there are more skin cancers than the combined number of cancers of the breast, colon, lung and prostate

About 90 percent of nonmelanoma skin cancer are associated with UV exposure from the sun

Melanoma

Key Points

Potentially deadly skin cancer
Caused by an abnormal proliferation of melanocytes (pigement making cells), and may be  initiated by various factors, most importantly sun damage to skin and hereditary predspostion
Initially presents as a newly formed mole or freckle or one which has changed in appearance,    or grows quickly
The number of melanoma cancers occuring has increased at an alrming rate.  1 in 55 people  will now develop melanoma in their lifetime
Melanoma is the most common form of cancer in young adults 25-29 years old

Common skin cancer, forming in the cells of the outer skin layer
Most cases caused by sun exposure, but may be the result of other factors
Consists of scaly, crusted lesions which are tender and slow-growing and may ulcerate

Squamous cell carcinoma (SCC) is a common skin cancer, which forms in the squamous cells, which make up the outer layer of skin. The condition typically presents in areas exposed to sun, such as the face, lips, ears hands, arms, and lower legs, though it may develop in other areas. It  sometimes develops on mucosal surfaces such as the genitals or mouth.  Lesions typically present as a scaly, crusted bumps or flat red or pink scaly spots, which may be tender and usually slow growing. They sometimes sting or burn or feel like a thorn is pricking the skin.  Lesions may develop sores and ulcerate.  Size of these cancers may be anywhere from very small to centimeters in diameter.When it is confined to the outer skin layer (the epidermis), it is called squamous cell carcinoma, in situ.  In situ is latin for 'in place' which describes the superficial growth pattern of this early squamous cell carcinoma.  If an SCC, in situ, is not treated, it will eventually invade.  SCCs which are invasive spread to deeper skin layers.  In a small percentage of cases, SCCs may metastasize, most often when located on the lip, ear, back of the hand, forehead or scalp.  In immunocompromsed patients, SCC's tend to be more aggressive in their growth and are at greater risk for metastasis.  

SCC is most often caused by excessive sun exposure. Other factors which may increase the likelihood of developing the condition include: family history, smoking, large burns, persistent ulcers, long-term use of immunosuppressants, and infection with a strain of human papillomavirus (which causes most genital SCCs). Any person previously treated for the condition is at increased risk as well. Anyone may be affected by the condition, but those with the fairest skin and most sun exposure have the greatest risk.

Basal Cell Carcinoma

Key Points
Most common form of skin cancer
Consists of bumps or growths which can be pearly or waxy, white, light pink, flesh-colored, or brown, sometimes slightly raised.  Commonly, BCC will scab or bleed intermittently
Frequently occurs in sun-damaged skin
Does not usually metastasize.  These are locally destructive cancers

Basal cell carcinoma (BCC) is the most common form of skin cancer. It usually presents in areas of the skin exposed to sun, including the face, neck, head, chest and upper back, though it can appear anywhere. There are several subtypes, including nodular, infiltrating, morpheic, and superficial.

In nodular BCC, the cancer presents itself as pearly, skin-colored or pink bumps, with tiny blood vessels often appearing on their surface. As the lesion grows, it may ulcerate or bleed with minor trauma. Infiltrating lesions often appear scar-like or depressed. They may often be shiny and have sores or scabs on their surface. Superficial BCC presents itself as pink or red scaly skin, often dry appearing.  Lesions will slowly grow and the border of the lesion may become raised. This can be mistaken as a chronic rash such as ringworm or just dryness. This subtype is generally found on the trunk, arms, and legs. While BCC can affect any age or ethnic group, it most commonly appears in elderly fair complected caucasians. Chronic sun exposure is virtually always noted as a causative factor.  There are also syndromes they convey a markedly elevated risk of BCC, such as nevoid Basal Cell Carcinoma Syndrome and Xeroderma Pigmentosa.

Actinic Keratosis

Key Points

Consist of small pink areas of skin which are rough or scaly
Caused by chronic accumulative sun exposure
*Considered a pre-cancerous condition

Actinic keratosis, also known as solar keratosis, is a precancerous condition related to damage from chronic sun exposure. Affected persons develop small pink or red lesions which are rough or scaly, usually appearing on parts of the body which are not typically covered by clothing. In some cases, squamous cell carcinoma develops within these lesions, which is the rationale for their preventative removal.  Any part of the body with consistent sun exposure, most commonly the face,  scalp, ears, neck, arms and top of hands, may be affected . Actinic keratoses are usually 1 centimeter or less in diameter, generally slightly scaly (with occasional instances of lesions which become thick with scale, as with warts), and with a pink, red or brown color variation.

Actinic keratoses most commonly affect fair-skinned persons, those who have trouble tanning (in other words, burn easily), those with light-colored (blue, green, hazel) eyes, and those with red or blond hair. Any person with excessive sun exposure, especially during their youth, is at greater risk.   In addition, persons with weakened immune systems due to HIV, chemotherapy or organ transplant have a greater risk of developing actinic keratoses and skin cancers.