Squamous cell carcinomas occur most often in skin cells that have experienced prolonged exposure to ultraviolet radiation, according to Mayo Clinic. The Skin Cancer Foundation says that the rim of the ears, face, lower lip, top of the head and neck are the areas most susceptible to SCC, along with the hands, arms and legs.
SCC is a slow-growing form of skin cancer and is relatively easy to treat if caught early, says WebMD. Unlike other skin cancers however, SCCs can spread to nearby lymph nodes, bones and other tissues, where it is more difficult to treat. Risk factors associated with developing SCCs include age, fair skin, light-colored eyes and hair, exposure to ultraviolet rays and inherited genetic susceptibility.
The Skin Cancer Foundation also points out that SCCs occur wherever there are squamous cells in the body. According to the National Cancer Institute, squamous cells line both the respiratory and digestive tracts and are also found in the linings of hollow body organs, such as the uterus and veins.
The Lung Cancer Research Foundation points out that SCC accounts for about 30 percent of all non-small cell lung cancers, and that NSCLCs makes up about 85 to 90 percent of all lung cancer diagnoses. Thus, SCCs account for approximately one-fourth of lung cancer cases. Smoking is a risk factor for these cancers.