What is Skin Cancer?
Your skin is your body’s largest organ. It covers and protects your body and helps regulate your body temperature. Your skin has three main layers: the epidermis, the dermis, and a layer of fatty tissue. Skin cancer usually forms in your epidermis, which is the outermost layer of skin. Your epidermis is made up of three main types of cells: squamous cells, basal cells, and melanocytes. Squamous cells are thin, flat cells in the upper layer of your epidermis. Basal cells are round cells below your squamous cells in your epidermis. Melanocytes are located deep in your epidermis and produce melanin, which is a pigment that gives your skin color, and causes your skin to tan after exposure to sun.
The two most common forms of skin cancer are basal and squamous cell carcinomas:
Basal cell carcinomas
Basal cell carcinomas are the most common type of skin cancer, accounting for about 80% to 90% of all cases. Basal cell carcinomas are usually slow-growing and rarely spread to your lymph nodes or organs; however, these tumors can eventually enlarge and invade nearby tissues if left untreated. Basal cell cancers are very common in the Caucasian population; it is estimated that there are as many BCC’s diagnosed each year as all other forms of cancer combined. Fortunately, the overwhelming majority of BCC’s are diagnosed at an early stage, when treatment is straightforward and long-term outcomes are excellent.
Squamous cell carcinomas
Squamous cell carcinomas are the second most common type of skin cancer, accounting for about 10% to 20% of all skin cancers. Squamous cell carcinomas are more aggressive than basal cell carcinomas, but not as aggressive as melanomas. These tumors are more likely to invade deeper layers of your skin and can spread to nearby lymph nodes or distant organs. As with BCC, if diagnosed early, the treatment of SCC is quite straightforward and long-term outcomes are excellent.