The incidence of malignant melanoma has soared to 18 times its level in 1930, meaning that 1 in 84 Americans will develop the virulent skin cancer over their lifetime, according to a study released Tuesday.
That's the fastest rate of increase of any cancer and translates into one American dying every hour from melanoma.
"Everybody sensed the risk was rising rapidly, but seeing the numbers is a little frightening," said Dr. Darrell Rigel, associate professor of dermatology at New York University Medical School, who presented his findings at the American Academy of Dermatology annual meeting in San Francisco.
"Melanoma is probably the most clear-cut case of preventable cancer," Rigel added in a telephone interview. "The problem is, can we get people to change their behavior?"
That's a challenge even in the North, where many residents sun themselves on local beaches in summer and fly south during winter.
Doctors have been warning for years about the rising rate of melanoma, the most aggressive form of skin cancer. Rigel's report, based on data from hospital tumor registries nationwide, offers the most comprehensive analysis of just how fast that rise is.
Melanoma already is the most common cancer in American women aged 25 to 29, and the second most common in women 30 to 34, behind breast cancer. It is the fifth most common overall nationwide _ behind lung, breast, colon and prostate cancers. That's a huge jump from 1980, when it was the 20th most common.
Some scientists suggest the apparent rise is overblown, resulting from physicians being better at recognizing melanomas that in the past went undiagnosed. But Rigel says the incidence of melanoma probably is underestimated because diagnosis and treatment increasingly is done in outpatient settings, while data is collected only in hospitals.
"Melanoma is the only major cancer where at some point the person having it may not hit a hospital," said Rigel.
Depletion of the ozone layer of the Earth's atmosphere, which lets in more cancer-causing ultraviolet light, is one reason researchers give for rising rates of melanoma.
Another is that people are spending more time in the sun and going out with less protective covering.
The best way to prevent melanoma is to follow the WAR rule, Rigel said: "Wear protective clothing. Avoid the midday sun where possible. Regularly use sunscreen."
At greatest risk for the cancers are individuals who have moles and freckles, light skin color, a family or personal history of melanoma, or a history of severe sunburn early in life.
On the rise
Risk of developing melanoma in U.S.:
1930 1 in 1,500
1980 1 in 250
2000+ 1 in 75