Monday, 7 October 2013

SKIN CANCER: Introduction,Causes & Remedies

Melanoma/Skin Cancer Overview

Skin cancers include melanoma, basal cell, and squamous cell. Basal and squamous cell are common and treatment is very effective. Malignant melanoma can be difficult to treat. Early diagnosis and treatment can increase the survival rate from melanoma.

Causes of skin cancer
HERE COMES THE SUN: The sun emits three forms of light: infrared (heat), visible light, and ultraviolet (UV) light. It is the latter that is responsible for skin damage: prolonged exposure can damage and kill skin cells, which then release chemicals that activate the body's pain receptors. The energy from UV light also stimulates the production of a pigment known as melanin, which causes the skin to darken, or tan. Melanin actually absorbs the UV radiation in sunlight, protecting skin cells from further damage. Melanin is produced gradually, which is why would-be tanners must build up levels of the protective pigment in their skin cells over the course of several days. It's also why darker-skinned people are less likely to burn or suffer from skin cancer than those of fairer complexion: they possess naturally high levels of melanin. In contrast, albinos don't have any melanin at all in their skin, hair, or irises because they are missing a critical enzyme required for its production.
SUNBURN: Sunburn occurs when skin cells are damaged by ultraviolet light. The body responds by increasing blood flow to the capillaries in the dermis layer of the skin to repair the damage, and this extra blood causes the redness of sunburn. Melanocytes are also responsible for developing skin cancer, caused when the cells mutate after repeated exposure to ultraviolet light. Surface reflections can increase the effects of ultraviolet exposure. For example, snow reflects 90 percent of ultraviolet light, which is why you can get a sunburn while skiing on a sunny day. Sand reflects as much as 20 percent of ultraviolet rays, perhaps one reason some people tan faster at the beach. Glass, however, absorbs ultraviolet light; this is why we don't get sunburned while driving or working in a glassed-in greenhouse.
ABOUT THE UV INDEX: The UV index is a standard measure of the amount of UV radiation striking the Earth's surface, and the most accurate measure of sun exposure risk. In the US, the UV index starts to increase in March and April, peaking every year in June. The ozone layer in the Earth's upper stratosphere absorbs most of the sun's UV radiation, but ongoing damage to that protective layer means that UV-related health risks continue to increase.

12 Ways to Protect Your Skin and Prevent Skin Cancer

1. All doctors are not created equal: When researchers from Emory University School of Medicine looked at the records of more than 2,000 melanoma patients, they found that those whose growths had been diagnosed by a dermatologist were more likely to have early-stage cancer — and to survive their disease — than those who'd been diagnosed by another kind of doctor. It may be that dermatologists are more skilled at finding smaller tumors — and less likely to brush them off as "nothing."
2. So-called harmless basal cell cancers aren't always so harmless: True, the growths are usually easy to remove, but of the million new cases each year, about 5 to 10 percent can be resistant to treatment, recurring over and over and requiring more extensive surgery. And some basal cells can be very aggressive, damaging the skin around them and even invading bone and cartilage. That's why if you have a suspicious growth, you should see a doctor promptly. "You want it removed before it disfigures your face," says Kishwer Nehal, M.D., director of Mohs and dermatologic surgery at Memorial Sloan-Kettering Cancer Center.
3. Your daily coffee fix may help you fend off skin cancer: For each cup of caffeinated java that you drink every day, there's a 5 percent drop in your odds of developing non-melanoma skin cancer later in life, researchers recently reported. Down a couple of Starbucks' venti coffees at 20 ounces apiece, and you may score a 30 percent drop in risk (or more — researchers didn't ask study participants about more than six cups a day). "It's possible coffee's antioxidant effect helps to protect against skin cancer," says Ernest L. Abel, Ph.D., professor of OB-GYN at Wayne State University School of Medicine. "But part of it may be that people who drink a lot of coffee tend to stay indoors more."
4. You can see a dermatologist for wrinkles a lot faster than for mole checks:In a study from the University of California, San Francisco School of Medicine, researchers posing as patients called more than 800 dermatologists across the country to see how long it would take to get different kinds of appointments. The disturbing results: When "patients" asked for a Botox treatment, the typical wait was eight days. But when their request concerned a changing mole, it went up — to 26 days, on average. Doctors may argue that the current state of health insurance has driven them to sometimes favor cosmetic patients, who pay in full on the day of treatment (insurance companies can take months to reimburse with only a fraction of the fee). Still, a changing mole isn't a trivial symptom. Make sure the receptionist knows why you need an appointment. If that doesn't work, ask your primary-care doc to intervene or to recommend another specialist.
5. SPF is only half the story: By law, sunscreen labels must list the familiar sun protection factor, which tells you how effectively the product blocks UVB rays, the ones primarily responsible for sunburn. But there's no rating system yet for how well a sunscreen stops UVA rays, which penetrate deeper into the base layer of the skin and can cause dangerous cell changes. The FDA has proposed a new sunscreen rule that would include label revisions for UVA. Until they're in place, David J. Leffell, M.D., professor of dermatology and surgery at Yale School of Medicine, recommends choosing a broad-spectrum sunscreen, which offers greater UVA (as well as UVB) protection.
6. If you live in Fargo, ND, and always use sunscreen, your risk of melanoma can be greater than your friend's in Miami: For years, researchers had puzzled over the fact that sunscreen users seemed more likely to develop melanoma than those who didn't protect themselves. But now scientists from the University of California, San Diego, may have figured out why. In a recent study, they found that the unexpected connection applies mainly to people with fair complexions in northern latitudes (north of Philadelphia or Boulder). They speculate that sunscreen users in northern areas never feel the burning that would warn them to cover up or get out of the sun because their lotions do a good job of blocking UVB rays. But meanwhile, they're being exposed to hundreds of times more cancer-causing UVA rays than they'd be able to tolerate if they weren't using sunscreen. Bottom line: Whatever your latitude, you need to practice sun-safety measures.
7. You're not fooling anyone with your tanning-bed habit — especially your skin: Despite what the salon receptionist may say, there's no evidence that browning yourself in a bed is any safer than doing it at the beach. "Even though there are federal guidelines for the amount of time someone should spend in a tanning bed, we know these are not always followed," says Michael J. Franzblau, M.D., clinical professor of dermatology (emeritus) at the University of California, San Francisco.
8. Like children, skin cancers don't always follow rules: The ABCDE rules for melanoma have been well publicized, but not all melanomas conform. One type, amelanotic melanoma, for example, has no brown or black. Another kind, nodular melanoma, is often symmetrical, with fairly regular borders and few colors, says David Polsky, M.D., Ph.D., assistant professor of dermatology and pathology at NYU Medical Center. And invasive melanomas can be smaller than six millimeters — the guideline in the ABCDE rules. The rule for you: Don't dismiss an odd-looking or changing mole because it doesn't resemble the textbook example; show it to a dermatologist.
9. If you're dark skinned, skin cancer is far less common — and far more likely to be fatal: No one's sure why, but among African Americans, Asians, and Hispanics, UV radiation does not play as strong a role in squamous cell carcinoma and melanoma as it does in Caucasians, says Hugh Gloster, M.D., associate professor of dermatology at the University of Cincinnati. He has found that non-Caucasians are far more likely to develop melanoma on the soles of the feet and palms of the hands than on areas that are more heavily sun-exposed like the face and chest.
10. You really can get skin cancer where the sun don't shine: The same human papillomavirus (HPV) that's responsible for cervical cancer can cause squamous cell carcinoma of the genitals. While squamous cell growths have at least a 95 percent cure rate overall, those in the genital region tend to be found later, which lowers your odds of survival, says Martin A. Weinstock, M.D., Ph.D.
11. Your husband may not be much help around the house, but when it comes to skin cancer, he could be a lifesaver: Working with a partner significantly ups the regularity of skin exams, reports June K. Robinson, M.D., professor of clinical dermatology at Northwestern University's Feinberg School of Medicine. And that could make all the difference: Previous studies have found that melanoma deaths could be lowered by as much as 63 percent if people performed monthly self-exams.
12. Painted toes look pretty, but what lies beneath may be deadly: Melanoma of the foot can hide under and around the nails and between the toes. And because this cancer has usually spread by the time it's diagnosed, it has a fatality rate of 50 percent. If you polish your toes, remove the color at least once a month and inspect your whole foot, including the sole. Also, don't forget sunscreen — on the tops and soles of the feet, says foot and ankle surgeon Neil Campbell, D.P.M.
shailesh kr shukla

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