Doctor, what do I need to know about skin cancer? (Part one)
Summer is upon us, and so far it has been a scorcher. Now more than ever it is important to know about skin cancer and know what you can do to protect yourself from it.
Skin cancer is the uncontrollable growth of abnormal cells in a layer of the skin. It attacks one out of every seven Americans each year, making it the most prevalent form of cancer. Fortunately the majority of all skin cancers can be cured if detected early and treated in time.
Excessive exposure to the ultraviolet radiation of the sun is the most important preventable cause of skin cancer. The spectrum of ultraviolet radiation can be broken into separate groups based on wavelength. UVB radiation is the primary mutagen responsible for photocarcinogenesis, while UVA radiation has a contributing role through the generation of reactive oxygen species. Another striking difference between UVA and UVB radiation is that while UVB radiation is less on cloudy days and toward the morning and evening hours, UVA stays constant throughout the day and is unaffected by cloud cover. People in southern regions, where the sunlight is more intense, are more likely to develop skin cancer. California trails only Arizona as being the state with the greatest number of skin cancer cases. Not all skin cancers are sun related - other possible causes include genetic factors and immune system deficiencies.
Basal cell carcinoma is the most common form of skin cancer and develops in 300,000 to 400,000 persons in the United States each year. Although this disease does not usually spread to other parts of the body through the blood stream, it may cause considerable damage by direct growth and invasion.
Squamous cell carcinoma is the second most prevalent skin cancer in the United States, affecting 80,000 to 100,000 persons per year. This disease can spread to other parts of the body and causes about 2,000 deaths per year.
Finally there is melanoma. Nearly 75 percent of all skin cancer deaths are from melanoma. The American Academy of Dermatology estimated that 105,750 new cases of melanoma were diagnosed in the United States in 2005. One American dies from melanoma almost hourly (every 68 minutes). If detected in the early stages, melanoma usually can be treated successfully. Let’s take a closer look at melanoma.
Melanoma can strike anyone. Caucasians are 10 times more likely to be diagnosed with melanoma than other races. However, even among Caucasians, certain individuals are at a higher risk than others. For example:
- Your chances increase significantly if you’ve already had one melanoma.
- You have a substantially increased risk of developing melanoma if you have many moles, large moles or atypical (unusual) moles.
- Your risk is increased if a blood relative, e.g., your parents, children, siblings, cousins, aunts, uncles, have had melanoma.
- If you are a Caucasian with fair skin, your risk is four times as great as a Caucasian with olive skin.
- Redheads and blondes have a two-fold to four-fold increased risk of developing melanoma. Blue or green eyes also increase your risk of developing melanoma.
- Excessive sun exposure in the first 10 to 18 years of life increases your chances of developing melanoma.
- Five or more sunburns double your risk of developing skin cancer.
Next month: Part two will provide information on early detection of melanoma, prevention and treatment.