A study conducted by Columbia University Medical Center researchers shows that "fight-or-flight" hormones triggered by stress can accelerate the development of pancreatic cancer. Beta-blockers, which are known to inhibit these hormones, were found to increase survival in a mouse model of the disease. The research was published in Cancer Cell earlier this week.
The scientists studied mice that were genetically predisposed to developing abnormal growths in the pancreas. In this study, there were two groups of mice. One group was raised in stressful living conditions (confined to a small living area). The other group was raised in normal housing. After 14 weeks, 38 percent of the mice that lived under the stressful conditions were found to have neoplastic pancreatic lesions, a precursor to pancreatic cancer. In the group that was raised in normal housing, no lesions of this kind were observed.
"We know that you need a DNA mutation to start on the path to cancer, but our findings suggest that stress is doing something to move things along," said Timothy C. Wang, M.D., the study leader.
The researchers focused on that "something" in later studies and found that the stress the mice were experiencing was increasing the levels of catecholamines, the fight-or-flight hormones, in the bloodstream. Those catecholamines then promoted nerve growth in the pancreas, which promoted tumor development, and then lead to an increase in production of more catecholamines.
"In other words, stress sets up what we call a feed-forward loop between nerves and cancer cells that promotes tumor development," said Wang.
With a different mouse model for pancreatic cancer, the team also found that treating mice with chemotherapy and nonselective beta-blockers helped the mice live longer than if treated with chemotherapy alone. The researchers also looked at survival in 631 patients and found that those who took nonselective beta-blockers after surgery had a median survival of 40 months, about two-thirds longer than patients taking selective beta-blockers or neither type of beta-blocker.
Wang notes that clinical studies still need to be performed before beta-blockers can be recommended to patients, but there is plenty of potential. For now, Wang recommends to patients to have a positive outlook on their health. It may not change their prognosis for pancreatic cancer, but it can't hurt.