What Is the Most Common Type of Skin Cancer?

According to the Skin Cancer Foundation, skin cancer is the most common form of all cancers in the United States, with more cases than lung, prostate, colon and breast cancer combined. There are three main types of skin cancer: melanoma, squamous cell carcinoma and basal cell carcinoma. All can be caused by excessive sun exposure, and all are treatable if discovered in time.

Basal Cell Carcinoma

The most common skin cancer is basal cell carcinoma. The American Cancer Society states that this cancer develops in areas of the body that are most often exposed to the sun and begins in the basal cells, which are the bottom cells on the external layer of skin. More than 1 million people are diagnosed with basal cell carcinoma each year in the United States, but it does not usually result in death as it rarely spreads to other parts of the body. Prognosis is good, and treatment usually involves simple removal of the carcinoma.

To detect basal cell carcinoma, look for moles or bumps that are getting larger, and notify your physician of any changes.

Squamous Cell Carcinoma

The second most common form of skin cancer is squamous cell carcinoma. It often starts as a flaky or scaly patch of skin called "actinic keratosis," but it can eventually spread to other parts of the body. According to the American Academy of Dermatology, squamous cell carcinomas can end up damaging the skin that surrounds the actinic keratosis, which results in that skin being removed along with the cancer, such as in a part of the ear lobe or nose. While not as dangerous as melanoma, if left untreated, squamous cell carcinoma can spread throughout the body and lead to death.

To check for squamous cell carcinoma, keep an eye on any flaky patches of skin or wounds that don't heal, especially with growths underneath them, and report them to your doctor.

Melanoma

Melanoma is the most deadly type of skin cancer, but it is not as prevalent as carcinoma. It starts in the melanin pigment of the skin and can spread outward or inward. The University of Maryland Medical Center reports that melanoma can spread throughout the body by way of the lymph system and is responsible for up to 75 percent of all skin cancer fatalities. If detected in the early stages, however, it is 100-percent treatable.

To check for melanoma, look for changes in size, shape and tenderness of a mole or dark spot on the skin. Report any changes to your physician.