Skin cancer is the most common type of cancer in the United States.  The three most common types of skin cancer are squamous cell carcinoma, basal cell carcinoma, and melanoma.  Nearly two million Americans develop either squamous or basal cell carcinoma every year.  Nearly 60,000 cases of melanoma, which strikes primarily those in their 20s, are expected to be diagnosed in 2005 alone.  All three of these common types of skin cancer are caused by long term or excessive exposure to the sun and other sources of UV rays (i.e. tanning beds). 

The signs of skin cancer largely depend on the type of cancer that one develops.  People who develop basal cell carcinoma will often develop tumors on the skin, some of which enlarge so slowly that they go unnoticed for a long time.  Some tumors, however, may grow as much as one-half an inch each year.  Signs of skin cancer can include raised bumps that can break open and form scabs at the center.  Flat pale or reddish patches resembling scars and thick and whitish borders around skin marks may also be signs of skin cancer.  Basal cell carcinoma often bleeds, scabs, and heals, causing a person to mistake the signs of skin cancer for a wound or sore.

The signs of skin cancer are slightly different for patients with squamous cell carcinoma.  Fair skinned people are more likely than darker skinned people to develop this skin cancer.  Squamous cell carcinoma typically begins with a red area of skin that becomes scaly and crusty and does not heal.  Over time, this sore may become firm and raised and may eventually become an open sore growing into underlying tissue.  These signs of skin cancer are characterized by a thick, scaly, and irregular shape.  In Bowen's disease, an early form of squamous cell carcinoma, the signs of skin cancer may include red-brown skin discoloration with a scaly or flat crusted region that may resemble psoriasis or ringworm.

The signs of skin cancer in patients with melanoma are also unique.  Signs of skin cancer of this type can develop in pre-existing moles (birth marks) or on normal areas of sun-exposed skin.  This type of skin cancer can vary in appearance.  Some are irregular shaped brown splotches with black spots, some appear as a black or grey firm lump, and still others are raised patches of brown with black, blue, red, or white spots.  Warning signs of melanoma can include growth of a pigmented mole or skin spot, changes in the color of an existing mole, size and shape changes, and bleeding or ulceration of an existing mole.

When you or a loved one notices the signs of skin cancer or any other unexplained changes in the skin, it is important to seek medical attention.  Most cases of skin cancer are treatable if detected and treated early.  It is also important for people of all ages and skin types to protect their skin from exposure to the sun.  Consistent use of sunscreens and sun blocks with a high SPF and active ingredients like titanium dioxide and zinc oxide can greatly reduce the risk of skin cancer.  To learn more about the signs of skin cancer you may wish to confer with your primary doctor, dermatologist, or other skin care professional.