Sun Exposure/Skin Cancer

1. Skin Cancer Information Presentation brought to you by Third Period Med-Tech Human Anatomy and Physiology

2. Sun Exposure/Skin Cancer • One in five Americans develop skin cancer some time in their life. • Over exposure to UV radiation in sunlight damages the DNA base. • Sun burnt skin accelerates production of Fas. • Fas- protein that causes genetically damaged cells to destroy themselves, which reduces risk of cancerous cells. • Newly developed skin lotion contain oily vesicles that have enzymes which initiate repair off DNA mutations caused by sunlight.

3. Basal Cell Carcinoma • It is the least malignant, but the most common skin cancer • The cells proliferate and invade the dermis and hypodermis. • At first, it appears as a shiny, dome-shaped nodule and then develops into a pearly ulcer with a beaded edge.

4. Basal Cell Carcinoma • It occurs most often on the parts of the face with the most sun exposure such as the nose. • It is slow-growing and is often caught before it gets too serious and metastasis occurs. • Surgery is effective in eliminating the cancer in 99% of cases.

5. Squamous Cell Carcinoma • Squamous cell carcinoma arises from the keratinocytes of the stratum spinosum. • It appears as a scaly, reddened papule. • It arises on the head (scalp, ears and lower lip), and the hands. • It tends to grow rapidly and metastasizes if not removed. • If it is caught early and removed with surgery or radiation, the chance of a complete cure is good.

7. Melanoma Melanoma is the cancer of melanocytes, most dangerous skin cancer because it’s highly metastatic and resistant to chemotherapy Counts for 5% of skin cancers Key to survival of Melanoma is early detection Melanoma can begin wherever there is pigment, 1/3 is from pre-existing moles (Brown to Black) Usual therapy for Melanoma is wide surgical excision accompanied by immunotherapy (immunizing body against cancer cells)

9. ABCD Rule The ABCD Rule is used to recognize melanoma. A- Asymmetry : the two sides of the pigmented spot or mole do not match. B- Border Irregularity : the borders of the lesion exhibit indentations. C- Color : the pigmented spot contains several colors (blacks, browns, tans, sometimes blue or red) D- Diameter : the spot is larger than 6 millimeters (the size of a pencil eraser) Some experts have found that adding “E” for Elevation above the skin surface, improves diagnosis.

10. Aging of the Skin- Infancy to Adolescense • During infancy and childhood skin thickens, sweat glands increasingly begin to function, more subcutaneous fat is deposited. • During adolescence skin and hair become oilier due to activated sebaceous glands. (subside at age 20 to 30) • After Acne clears, skin shows accumulative damage and skin inflammation called dermatitis.

11. Aging of the skin- Old Age • Old age causes skin to become thinner, epidermal cell replacement slows down, and skin becomes more susceptible to bruises and injuries. • The subcutaneous fat layer diminishes, leading to an intolerance of cold. • Decreasing elasticity of the skin and loss of subcutaneous tissue lead to wrinkling. • Decreasing number of melanocytes and Langerhans’ cells enhance the risk of skin cancer. • By the age of 50, hair follicles decrease by 2/3.