EXPERTS DISAGREE OVER DEADLY SKIN CANCER
The nation is in grip of what looks like a terrifying melanoma epidemic: Melanoma is being diagnosed at more than double the rate it was in 1986, increasing faster than any other major cancer.
But why the numbers are increasing is a contentious subject, so touchy that one dermatologist called it “the third trail of dermatology”.
In the study, in the current issue of the British Medical Journal, Dr. H. Gilbert Welch of the department of veterans’ affair in white river junction, Vt., and Dartmouth Medical School and his colleagues analyzed melanomas changing incidence and death rate. They used Medicare data to track the swift rise in melanoma cases since 1986 and data compiled by the National Cancer Institute to track the death rate and the number of people with early and late-stage disease.
They found that since 1986, skin biopsies have risen by 250 percent-nearly the same as the rise in the incidence of early stage melanoma. But there was no change, they found.
Welch and two colleagues, Dr. Steven Woloshin and Dr. Lisa M. Schwartz, argue that if there were really an epidemic of melanoma-for example, if something in the environment was causing more to get the skin cancer-scientists should see increases in cancers at all stages. This is what happened with lungs cancer caused by smoking, and with other cancers caused by toxic substances.
The fact that the increase was seen only in very early stage disease was a tip -off that the epidemic might be less than it seemed, Welch said. And that, he says, leads to a difficult question. The point of screening melanoma is to reduce the death toll from cancer. But if screening has not altered the number of patients with advanced disease of patients or lowered death rate, what is its benefit?
”That’s the million dollar question,” Welch said. “It certainly rises question about whatever we’re doing any good.” The researchers hastened to add that people who notice suspicious moles or spots should not hesitate to see the doctor. But they said skin cancer screening id directed at healthy people who have no reason to suspect that anything is wrong.
The federal preventive services task force, which makes screening recommendation, has said that there was insufficient evidence to recommend either for or against skin screening, but the American Academy of Dermatology.
Speaking for the dermatology academy, one of its past presidents, Dr. Darrell Rigel, a dermatologist in New York, and said it made sense to look for melanomas and remove them before they spread. “And there’s another thing we know with melanoma that’s very clear the earlier, the better the survival.’’
Rigel questioned Welch’s conclusion that the increase in biopsies was leading to excessive diagnosis of melanoma. ”I would say the inverse is more likely,” he said. “There are more melanomas and therefore more biopsies.”
At the American Cancer Society, Dr Len Lichtenfeld, an oncologist, said his group reviewed the same data is Welch and came to a different conclusion. Screening he said, appears to be saving lives.
As evidence he pointed to a trend in the data indicating that the death rate from the disease rose slightly year by year until about a decade ago. That is consistent with an increase in serious cases of uld be expected if screening was working.
Welch disagree, he said the death rate has been basically flat since 1986, although it bounces around slightly from year to year as a result of statistical fluctuations.
“We don’t disagree about the data,” Welch said. “We disagree about the interpretation. We are not arguing that there is zero change in disease burden. We are arguing that most of the newly diagnosed cases are the result of increased screening.”
Others who study cancer screening that Welch’s arguments were convincing add that he raised sues about the national melanoma epidemic that could not easily be dismissed.
Dr. Barnett Kramer, associate director of the office of disease prevention at the National Institute of Health, said the ideal way to know if a screening program works is to do a randomized clinical trial, assigning some people to screening and not others, then seeing if the screening saved lives.
Absent such a study, he said, he finds Welch’s paper convincing. “It does not look like our melanoma awareness campaigns have made an impact on mortality or on late-stage disease,” Kramer said.
That also is the view of Dr. A. Bernard Ackerman, emeritus director of the Ackerman Academy of Dermatopathology in New York. Dermatologists have gone too far he said, with screening clinics, removing innocuous moles and diagnosing melanoma freely. “There has been a mania for taking off these moles that are of no consequence,” Ackerman said.
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