NATIONAL CANCER INSTITUTE, LINDA BARTLETT
Relax, seems to be the message. Mice that showed higher levels of stress and anxiety during behavioral tests were more likely to come down with an aggressive form of skin cancer when exposed to repeated doses of UV light than those that were less anxious, according to a study published in PLoS ONE last week (April 25).
"It's bad enough that cancer diagnosis and treatment generates stress and anxiety, but this study shows that anxiety and stress can accelerate cancer progression, thus perpetuating a vicious cycle," said first author Firdaus Dhabhar in a press release.
Dhabhar and colleagues tested for the natural level of stress in mice by placing them in a maze with dark corridors, and mazes with hidden passageways, and measuring the amount of time each animal spent in the darker or hidden areas. The mice that were less likely to venture out were deemed to be more anxious. All mice, which were hairless, were then exposed to UV radiation three times per week for 10 weeks.
Although all of the mice eventually developed skin cancer, the anxious ones were more likely to develop an aggressive form. In addition, they also had a larger number of T-regulatory cells, which can act to hide the cancer from immune system attack, and higher levels of the stress hormone corticosterone.
(Hat tip to FierceBiotech Research)