Skin Cancer

John McCain declared Monday he has been cancer-free since a bout with skin cancer 7 1/2 years ago, although the presumptive Republican presidential nominee underwent a full medical examination -- including a cancer screening -- earlier in the day. The Arizona senator pledged to release the results before the end of April, the same time frame for releasing his income tax returns.

Melanomas like those suffered by Sen. John McCain are more lethal than other types of skin cancers because the pigment-producing melanocytes that produce them are actually not skin cells at all. Though the basal cells and squamous cells that are responsible for the most common types of skin cancer are integral parts of the skin from the beginning, melanocytes are visitors -- nerve cells that are produced in the spinal column during infancy before migrating to the skin.

Exercise and moderate caffeine consumption together could help ward off sun-induced skin cancer, researchers said Monday. Experiments on mice showed that caffeine and exercise together somehow made them better able to destroy precancerous cells whose DNA had been damaged by ultraviolet radiation, scientists at Rutgers University in New Jersey reported in the Proceedings of the National Academy of Sciences.

Under pressure from Congress, government regulators Thursday proposed new "truth in labeling" rules for sunscreen to give consumers clearer, more complete information on protection against cancer-causing ultraviolet rays. Once finalized, the rules would require manufacturers to test products for protection against two types of ultraviolet rays instead of one, as is now standard.

When my father was 11, his family uprooted itself from Burlington, Vt., and moved to Southern California. The reason was straightforward: My father suffered from psoriasis and his doctors said that lots and lots of sunshine was what he needed. For 60 years, he was diligent about following their advice, sunbathing whenever he had the opportunity. His psoriasis improved, but the years of sun exposure ultimately took their toll.

California is experiencing a "developing epidemic" of melanoma among Latinos, according to a study by USC researchers released Monday. Although the incidence is still much lower among Latinos than among whites, the researchers are alarmed because the greatest increase is in the rate of so-called thick tumors, which are much more likely to be lethal, according to a report in the journal Cancer.

For years we've been told to slather on sunscreen, wear hats and avoid the sun. Now, with new data on the benefits -- and widespread deficiency -- of vitamin D, some scientists and doctors say we may have gone overboard. According to the American Cancer Society, more than 1 million people will be diagnosed with skin cancer this year, almost always because of too much sun. It's no wonder that dermatologists and cancer specialists urge people to protect themselves. But Dr.

African Americans are three times more likely than whites to be diagnosed with skin cancer when it is already in an advanced and possibly fatal stage, according to a study in Miami released Monday. Researchers pointed to a lack of public awareness about the risks of skin cancer for African Americans as well as Latinos, who are nearly two times more likely than whites to have a late-stage diagnosis. The research focused on melanoma, the deadliest form of skin cancer.

MANY of us are, shall we say, rather haphazard sunscreen users -- a fact that makes dermatologists apoplectic. But, in this era of evidence-based medicine, three nagging questions remain: How much do we really need to worry about skin cancer? How tightly linked are sun exposure and skin cancer? And how good is the evidence for the cancer-protective effect of sunscreens? The answers are complex.