Stay calm, folks: Highly anxious mice developed more aggressive cancer
Cancer is bad enough. But anxiety could make the disease even worse as it progresses, Stanford University School of Medicine researchers believe. The key to minimizing the damage, however, may be simply keeping calm, cool and collected. And Valium could potentially help (more on that in a bit).
The finding, published April 25 in PLoS One online, builds on previous research that shows chronic stress can heighten the risk of getting cancer and other diseases. But the key here is "anxiety"--the scientists say their study is the first of its kind to directly connect high levels of anxiety to a more severe onslaught of accelerated, aggressive cancer.
Hairless, anxiety-prone mice were crucial tools toward making the discovery. First, they needed to determine what constitutes an overload of stress. They theorized that anxious mice would likely avoid danger, so they placed a number of hairless mice on a raised, cross shaped track that had both an open walkway and one concealed by walls. They also tested the rodents in a large box that was half dark and half filled with light. Scientists sifted out the anxious mice by pulling the ones out that avoided the dark part of the box and the enclosed walkway, like when people decide to avoid a dark alley in case of crime.
Once they had their anxious, hairless mice, the scientists exposed them to ultraviolet rays similar to what humans may face with too much sun exposure (10-minute blasts of radiation, three times per week for about 10 weeks). It turns out that the anxious mice developed more tumors than the calm ones and came down with invasive types of cancer, while the calm ones did not (all developed skin cancer). What's more, the nervous mice developed greater amounts of regulatory T cells, which suppress the immune system, and the anxious rodents also secreted much higher levels of corticosterone, a hormone that kicks in during stress and disease.
Yes, a finding like this in anxious, hairless mice isn't necessarily going to happen in humans. But the researchers say they will plow ahead to hopefully test the theory in human trials. More immediately, they will test to see if reducing the negative effects caused by anxiety and stress will boost how well a cancer treatment works. A regular dose of Valium over a short period of another anxiety medication might do the trick, said first author Firdaus Dhabhar, who is also a stress expert and immunologist at the Stanford Cancer Institute and Stanford Institute for Immunity, Transplantation and Infection.
"The goal," he said in a statement, "is to ameliorate or eliminate the effects of anxiety and chronic stress, at least at the time of cancer diagnosis and during treatment."