Exposure to ultraviolet radiation causes skin cancer. There is no such thing as healthy sun tan, and both UVA and UVB rays can cause cancer. Ultraviolet radiation, like other forms of radiation, can disrupt the replication of DNA during cell division, causing the proteins to line up in the wrong order, leading to harmful mutations that turn into cancer.
Skin Pigment
The pigment in our skin comes from cells called melanocytes. They are activated by sunlight to rise to the surface of the skin, acting as an "umbrella" to shield the DNA of skin cells from the harmful radiation. Tans fade as the skin cells are sloughed off about every 30 days.
Types of Skin Cancer
The three types of skin cancer are basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Having fair skin or a severe sunburn in childhood puts you at greater risk for skin cancer.
Basal Cell Carcinoma
This is the most common--and least dangerous--type of . It rarely spreads to other organs, and starts as a small, shiny bump that gets a central depression with a pearly edge.
Squamous Cell Carcinoma
These are raised, reddened and scaly bumps, forming an ulcer usually found on the scalp, ears, lower lip or back of the hand. With early detection, this is easily treatable, but can be deadly if ignored.
Malignant Melanoma
This is the most deadly skin cancer, accounting for about five percent of all skin cancer cases. It often arises from a prior mole. To see if your mole may be malignant, follow the ABCD test:
Asymmetry--the mole is oddly shaped, not round; Borders are irregular; Color is faint in some spots, or there is more than one color; Diameter is larger than 6 mm (the size of a pencil eraser).
Tags: skin cancer, cell carcinoma, skin cells,