Speaking of potential large markets, here's a recent report on skin cancer (in humans):
P H I L A D E L P H I A, Feb. 17 - People with light
skin and fair hair may be asking for trouble if they
think sunscreen can protect them from deadly skin
cancer, medical researchers warned today.
A study by the Sloan-Kettering Cancer Center suggests
the risk for melanoma, one of the fastest-rising forms of
cancer in the United States, depends mainly on genetic
factors such as hair, skin and eye color, and the number of
moles a person has.
For example, the study estimated that people with blond
or red hair, light-colored eyes and pale complexions were
almost six times more likely to contract melanoma than those
with darker features.
But the sun still poses a danger, especially for those who
are genetically susceptible to the disease, and researchers
said sunscreens may compound the problem by eliminating
sunburn and allowing fair-skinned sunbathers to stay
outdoors for longer stretches.
"Based on the evidence, we conclude that sunburn itself
probably does not cause melanoma, but that it is an important
sign of excessive sun exposure, particularly among those who
are genetically susceptible because of their skin-type," said
Dr. Marianne Berwick, a Sloan-Kettering epidemiologist.
Melanoma Rates Up, But People Inside
Her study, due to be presented to the American Association
for the Advancement of Science today, also suggests
paradoxically that incidence rates for melanoma may be rising
because people nowadays go outside less often.
"Chronic sun exposure may be protective for the
development of melanoma because the skin has adapted to
the sun," Berwick said. "On the other hand, intermittent sun
exposure appears to increase risk, making it much less
protective."
Once a very rare disease, malignant melanoma has been
rising at alarming rates among whites in recent decades.
Melanoma is the 10th most common cancer in the United
States. But it is the fastest-rising form of cancer for American
men and the second for women, after lung cancer.
In Australia and New Zealand, melanoma is the fourth
most common form of the disease.
Ozone Layer Depletion Usual Scapegoat
Rising skin-cancer rates have been attributed to a depletion in
the Earth's ozone layer, which allows more of the sun's
harmful ultraviolet rays to penetrate the atmosphere.
But Richard Setlow, a biologist with the Brookhaven
National Laboratory, said in a scientific paper that 90 percent
of the sunlight linked to malignant melanoma belonged to a
spectrum of ultraviolet radiation known as UVA.
Ozone depletion, which involves a form of ultraviolet light
known as UVB, would be inconsequential to the incidence of
melanoma, he said.
Another researcher, Honnavara Ananthaswamy of the
M.D. Anderson Cancer Center, said UVB radiation may
cause other forms of skin cancer by inducing mutations in a
tumor suppressor gene known as P53, which normally
controls the proliferation of skin cells.
In a study funded by sunscreen manufacturers, the
researcher found that 96 percent of laboratory mice treated
with Sun Protection Factor 15 and exposed to UVB
radiation failed to develop the genetic mutation.
Ananthaswamy suggested sunscreens could be graded for
consumers according their ability to stop the genetic mutation
that leads to some forms of skin cancer.
"In addition to SPF...it may be possible to develop an
"MPF", or mutation protection factor, for sunscreens based
on their ability to inhibit P53 mutation," the researcher said. |
