A new study published in the journal Cancer Cell has showed that stress accelerates the development of pancreatic cancer by triggering the release of "fight-or-flight" hormones. Beta-blockers–commonly used medications that inhibit these hormones–were found to increase survival in a mouse model of the disease. An additional analysis of patients with advanced pancreatic cancer revealed that those who were taking selective beta-blockers lived approximately two-thirds longer than those who were not taking the medications.

Recent studies have shown that emotional and psychological stress play a role in the development of tumors in general. This effect is thought to occur through the sympathetic nervous system, which releases hormones that give the body a surge of energy so that it can respond to perceived dangers.

Some biologists dismissed this idea because stress is hard to measure. It is wondering how stress could possibly be related to a biological process that involves DNA mutations and the growth of cancer cells within a particular organ, such as the pancreas."

The current study was designed to find the links between stress and early development of pancreatic cancer. The researchers studied mice that are genetically predisposed to developing abnormal growths in the pancreas.

The mice were raised in stressful living conditions; control mice were raised in normal housing. After 14 weeks, 38% of the stressed mice were found to have neoplastic pancreatic lesions, a precursor to pancreatic cancer. No such lesions were observed in the controls.

Studies of the mice revealed that stress increases levels of catecholamines–the fight-or-flight hormones–in the bloodstream. Within the pancreas, catecholamines drive production of molecules that stimulate nerve growth around tumors.

The new nerves promote tumor development and make more catecholamines, perpetuating the cycle. In other words, stress sets up a feed-forward loop between nerves and cancer cells that promotes tumor development.

In experiments with a different mouse model of pancreatic cancer, the CUMC team demonstrated that treating mice with chemotherapy and nonselective beta-blockers, which are used to treat a variety of conditions, lived significantly longer than mice treated with chemotherapy alone.

The researchers also looked at survival in 631 patients who had surgery to treat advanced pancreatic cancer. Those who were taking nonselective beta-blockers after surgery had a median survival of about two-thirds longer than patients taking selective beta-blockers or neither type of beta-blocker.

The researchers said it would be premature to recommend the use of beta-blockers for these patients, until they conduct prospective clinical studies. However, beta-blockers could potentially become part of the overall treatment regimen for pancreatic cancer, the research team concluded.