Understanding Skin Cancer (Carcinoma)
Carcinoma is a type of cancer that can form when there has been damage to the DNA of the cells that make up the skin or tissue lining internal organs. A cell’s DNA contains instructions that tell it what to do. Normal healthy cells in the skin multiply, mature, and move toward the surface where they are shed as dead skin. Damage to the DNA causes the once healthy cell to mutate, have uncontrolled overgrowth, and gives the potential to become cancerous. Because the damaged cells do not die off like they should and continue to multiply, they crowd out the normal cells. Most DNA mutations in skin cells are caused by ultraviolet (UV) radiation found in sunlight and in commercial tanning lamps. Short term UV damage results in sunburn. Chronic UV damage leads to changes in skin texture, premature skin aging, freckling and potentially skin cancer. Other factors that result in a greater risk of developing skin cancer include a family history of skin cancer, fair complexion or genetic mutation. The three most common forms of skin cancer are squamous cell carcinoma, basal cell carcinoma and malignant melanoma.
The skin is the largest organ in the body and is made up of three layers; epidermis, dermis, and hypodermis (subcutaneous fat layer). The epidermis is the outermost layer of the skin that protects the body from UV radiation, chemicals, bacteria, viruses, and fungi. It is made up of several sublayers that work together to continually rebuild the protective surface layer of the skin. It is in this layer that skin cancer starts, primarily due to its exposure to UV radiation and environmental elements.
Melanoma is the most serious form of skin cancer. It forms in melanocytes which are cells located at the base of the epidermis. Melanocytes produce melanin, which gives color to the skin and helps protect the deeper layers of skin from harmful UV rays. Melanoma can also be genetic and can appear anywhere on the skin, not just areas exposed to UV rays. Melanoma is the deadliest of all skin cancers because it can spread quickly to other parts of the body, including internal organs. Early detection is crucial in treating melanoma.
Basal cell carcinoma (BCC) is the most common form of skin cancer. Basal cells are small, round in shape, and are found in the deepest layer of the epidermis. As these cells divide and create new cells, the old cells are pushed to the surface where they mature into squamous cells. If the basal cells become damaged at a DNA level, they do not mature. Instead, they begin overgrowing as a damaged cell and can become cancerous. While basal cell tumors can be small or large in size, they rarely spread to other parts of the body. BCC tumors are most common on the head and other parts of the body exposed to the sun’s UV rays.
Squamous cell carcinoma (SCC) is the second most common form of skin cancer. As basal cells push to the surface, they mature into squamous cells that are flat in shape. Squamous cells make up the top layer of the epidermis. This layer is the thickest layer of the epidermis and is involved in transferring certain substances in and out of the body. They produce keratin, a protective protein that makes up most of the structure of the skin, hair, and nails. As with the other forms of skin cancer, exposure to UV rays can result in damage and mutations to these cells causing overgrowth and the potential to become cancerous. The majority of SCC tumors are fairly slow growing, but if left untreated can spread to other tissues, bones, and lymph nodes, where it becomes more difficult to treat. This form of skin cancer often affects the face, ears, scalp, back of the hands, lower legs, shoulders, and chest area.
Although skin cancer can be genetic or from environmental elements, UV rays are the largest contributor in the development of skin cancer. Proper skin protection is key in reducing premature skin aging, changes in skin texture, freckling, and the potential of skin cancer. It is never too late to start using sunscreen, hats, and protective clothing to reduce your skin’s exposure to harmful UV rays. If you have a history of using tanning-beds or significant UV exposure without sun-protection, you may want to consider a skin exam by a dermatologist, especially if you have any moles or lesions that are changing or growing. Lesions that change in size, color and texture can be an indication of skin cancer, and early detection is not only the goal, but for patients with an undiagnosed melanoma, can be life-saving.