Does stress speed up the onset of skin cancer? The
answer, in mice anyway, appears to be yes. Scientists at
the
Johns Hopkins Kimmel Cancer Center say that chronic
stress may speed up the process in those at high risk for
the disease. Their new study, published in the December
issue of the Journal of the American Academy of
Dermatology, shows that mice exposed to stressful
conditions and cancer-causing UV light develop skin cancers
in less than half the time it took for nonstressed mice to
grow tumors.
The Johns Hopkins investigators say that if what they
are seeing in mice has relevance in man, stress-reducing
programs like yoga and meditation may help those at high
risk for skin cancer stay healthy longer.
"There's a lot of evidence pointing to the negative
effects of chronic stress, which dampens our immune system
and impacts various aspects of our health," said Francisco
Tausk, associate professor of
dermatology at Johns Hopkins and director of the study.
"But, to help create solid treatment strategies, we need a
better understanding of the mechanisms of how stressors
affect skin cancer development."
Tausk exposed 40 mice to the scent of fox urine
— the mouse equivalent of big-time stress — and
large amounts of UV light. The first skin tumor in one of
the mice appeared after eight weeks of testing. Mice
exposed only to UV light began developing tumors 13 weeks
later. By 21 weeks of testing, 14 of the 40 stressed mice
had at least one tumor, and two nonstressed mice had
tumors. Most tumors were squamous cell skin cancers, also
known as nonmelanoma cancers, which have the potential to
spread to other parts of the body.
Chronic stress is known to suppress the activity of
immune system cells that recognize foreign invading cells
and target them for destruction. Acute stress, which is
episodic and time-limited, such as parachuting or riding a
roller coaster, may have the opposite effect of chronic
stress. "Acute stress actually can rev up the immune
system," Tausk said.
Tausk and his team will conduct more studies to find
the cancer pathways influenced by chronic stress.
"Stress reduction programs usually are a good option
for many people, but we think they may be more important
for individuals at high risk for skin cancer," he said.
Fair-skinned people exposed to large amounts of UV
light and patients previously diagnosed with squamous cell
skin cancer, genetic diseases or organ transplants that
predispose them to the disease are considered high-risk.
The investigators urge people concerned about their
risk for skin cancer to speak with their health-care
provider before starting any stress-reduction or exercise
program.
This research was funded by the Johns Hopkins Center
for Complementary and Alternative Medicine. Participants in
this research are Jason Parker, Sabra L. Klein, Warwick L.
Morison and Xaobu Ye, all of Johns Hopkins; Martha
McClintock, University of Chicago; Claudio J. Conti, M.D.
Anderson Cancer Center; and Carlos Nousari, University of
Miami.