Basal and squamous cell Skin Cancers are the most common cancers of the skin. They develop from cells called keratinocytes, the most common cells in the skin.
Melanomas are Skin Cancers that develop from melanocytes, the cells that make the brown pigment that gives skin its color.
Melanocytes can also form benign growths called moles.
It is important for you to know what melanomas and basal and squamous cell Skin Cancers look like. That way, you can find them at the earliest possible stage, when they are cured most easily.
Basal and squamous cell cancers (keratinocyte cancers)
Basal cell cancers and squamous cell cancers are the most common cancers of the skin. They develop from skin cells called keratinocytes. Both basal cell and squamous cell cancers are found mainly on parts of the body exposed to the sun, such as the head and neck, and their occurrence is related to the amount of sun exposure over a person's lifetime.
These cancers (especially basal cell cancers) rarely spread elsewhere in the body and are less likely than melanomas to be fatal. Still, they are important to recognize. If left untreated, they can grow quite large and invade into nearby tissues, causing scarring, disfigurement, or even loss of function in some parts of the body.
Melanomas can occur anywhere on the body, but are more likely to develop in certain locations. The trunk is the most common site in men. In women, the legs are the most common site. Some experts think that melanomas develop more often in these spots because these areas are exposed to sun off and on and are more likely to get sunburned. Rarely, melanomas can also develop in other parts of the body, such as the eyes.
Melanoma occurs much less often than basal cell and squamous cell Skin Cancers, but it can be far more serious. Like basal cell and squamous cell cancers, melanoma is almost always curable in its early stages. But if left alone, melanoma is much more likely than basal or squamous cell cancer to spread to other parts of the body where it can be very hard to treat.
What is ultraviolet (uv) radiation?
Ultraviolet (UV) rays are a form of invisible energy given off by the sun. Ultraviolet radiation is divided into 3 wavelength ranges:
- UVA rays cause skin cells to age and can cause some damage to cells' DNA (the substance in each cell that controls its growth, division, and function). UVA rays are mainly linked to long-term skin damage such as wrinkles, but are also thought to play a role in some Skin Cancers.
- UVB rays are mainly responsible for direct damage to the DNA, and are the rays that cause sunburns. They are also thought to cause most Skin Cancers.
- UVC rays don't penetrate our atmosphere and therefore are not present in sunlight. They are not normally a risk factor for Skin Cancer.
Although UVA and UVB rays make up only a very small portion of the sun's wavelengths, they are mainly responsible for the harmful effects of the sun on the skin. UVB radiation can damage the DNA of skin cells. If this damage affects the DNA of genes that control skin cell growth, skin cancer may be the result. Recent research has found that UVA also contributes to skin cancer formation. Scientists now believe that both UVA and UVB rays damage skin and cause Skin Cancer. There are no safe UV rays.
Skin cancers are one result of getting too much sun, but there are others as well. The short-term results of unprotected exposure to UV rays are sunburn and tanning, which are forms of skin damage. Long-term exposure causes prematurely aged skin, wrinkles, loss of skin elasticity, dark patches (lentigos, sometimes called "age spots" or "liver spots"), and pre-cancerous skin changes (such as dry, scaly, rough patches called actinic keratoses).