Skin Cancer-Melanoma

By Bonnie Jenkins, Advanced Natural Medicine

Termed an "undeclared epidemic" by the American Academy of Dermatology (AAD), skin cancer affects an estimated 700,000 Americans yearly. Since I’m in the high-risk category – fair skinned with a history of more than a few severe sunburns – my doctor recently suggested that I have my skin evaluated by a dermatologist. It wasn’t a high priority on my “to do” list until I was reminded that skin cancer is the most prevalent of all cancer – more than one million new cases of the disease will be diagnosed in the U.S. this year alone. Skin cancer is a high profile disease, affecting celebrities like Elizabeth Taylor, John McCain and Maureen Reagan. For some reason, though, we never think it can happen to us – which is probably one reason the incidence and mortality of skin cancer increases every year.

Of the three forms of skin cancer – basal cell carcinoma, squamous cell carcinoma and melanoma, 80 percent of cases are basal cell carcinoma and 15 percent are squamous cell carcinoma. Fortunately, if detected early, both of these forms have a better than 95 percent cure rate. Melanoma, the deadliest and most virulent form of the disease, kills approximately 10,000 people each year. According to the AAD, that’s one person every hour. Yet the AAD also states that melanoma is curable when caught in the early stages.

Burn Baby, Burn

Overexposure to the sun is by far the greatest risk factor in skin cancer. Ultraviolet radiation (UV) affects the skin in a number of ways.

UVB rays, the burning rays, penetrate the top layers of skin and contribute to dry skin, wrinkles and age spots. UVA rays, sometimes called the silent killers, penetrate and damage skin at cellular levels. The combination of UVA and UVB rays oxidize skin cells, releasing reactive unpaired molecules that damage cell membranes and destroy genetic material. Over time, this diminishes the protective fatty layers of the skin, causing the proteins in skin (elastin and collagen) to link together or mutate, leading to cancer.

According to most dermatologists, the best way to prevent skin cancer is by using an SPF 15 or greater sunblock or sunscreen. Since there seems to be a good deal of confusion over these products, I called dermatologist David Stoll, M.D. to explain the difference. He said that sunblocks containing natural titanium dioxide or zinc oxide prevent UV rays from reaching skin by scattering the damaging rays. Sunscreens, on the other hand, absorb certain amounts of UV radiation (mostly UVB), rendering it harmless by turning it into infrared radiation (heat). But, Dr. Stoll was quick to note that the problem with either type of product is that most people simply don’t use enough. He recommends using at least one full ounce, or the equivalent of a shot glass from head to toe. For the maximum protection from your sunblock or sunscreen, Dr. Stoll also suggests applying the product at least a half-hour before heading outdoors and reapplying it every two hours throughout the day.

It seemed like a good starting point. But since I can burn even on a cloudy day, I wondered if there was anything else I could do to tip the odds in my favor. James M. Spencer, M.D., associate professor in the department of dermatology at Mount Sinai School of Medicine had the answer. He said that there is a growing body of research connecting diet and UV protection. He points to two promising groups of chemopreventive, antioxidant agents derived from plants - polyphenols and isoflavones -that have also had favorable results preventing and, in some cases, reversing cell damage caused by erythema, the first noticeable stage of sun injury.

Block the Sun From the Inside Out

Among the many sources of polyphenols, those found in green tea are rich in antioxidant activity and have skin-protective qualities. In one study, skin treated topically with green tea extracts showed a reduced number of sunburn cells and protection of certain immune-boosting cells. The researchers concluded that green tea extracts reduced the DNA damage that formed after exposure to UV radiation.

Although the research focused primarily on topical applications, there is evidence that oral supplements provide cancer protection as well. Drinking several cups of green tea daily has been shown to limit damage to normal tissues exposed to chemotherapy and ultraviolet radiation. Another powerful source of chemoprotective polyphenols is grape seed extract (Vitis vinifera), which also acts as a potent antioxidant, mopping up the reactive molecules that cause oxidative stress and stabilizing cell membranes.

The isoflavones in soybeans and red clover contain genistein, which appears to provide another source of UV protection, thanks again to potent antioxidant activity. Dr. Spencer notes that genistein also has the ability to disrupt signal transduction pathways related to tumor promotion.

Carotenoids have also gained a reputation for their ability to protect against UV damage. Personally, I’ve found that if I increase my intake of beta-carotene three or four days before a day in the sun, I’m far less likely to burn. But now, an exciting new study has found that taking just 24 mg. of two other carotenoids, lutein and lycopene, every day can lessen the intensity of a sunburn and hence, the damage.

One Last Thing ...

A few days ago, I came across a disturbing article in USA Today that brings home the dangers of radiation. While the sun exposes us to fairly high levels of radiation, a new study has found that low-energy radiation may play a greater role in causing cancer than originally thought. Using a beam of low-level radiation – about 1,000 times weaker than sunlight and far lower than the level at which damage was thought to occur in cells – the researchers discovered a chain reaction which splintered RNA molecules. RNA molecules are the helper molecules cells use to carry out genetic instructions. Although much more research needs to be done before any responsible conclusions can be made, this should provide food for thought to anyone undergoing radiation therapy. On the up side, if these findings bear out in future research, it may well lead to a new generation of safer ways to diagnose diseases, ultimately replacing mammograms, CAT scans and other radiation-based imaging tools commonly used for routine screenings.

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References:

Bickers DR, et al. “Novel approaches to chemoprevention of skin cancer.” Journal of Dermatology. 2000; 27:691-695.

Elmets CA, et al. “Cutaneous photoprotection from ultraviolet injury by green tea polyphenols.” Journal of the American Academy of Dermatology. 2001; 44:425-432.

Heinrich U, et al. “Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema.” Journal of Nutrition. 2003; 133:98-101.

Widyarini S, et al. “Isoflavonoid compounds from red clover (Trifolium pratense) protect from inflammation and immune suppression induced by UV radiation.” Photochemistry and Photobiology. 2001; 74:465-470.