ScienceDaily (Jun. 10, 2008) — Scientists have been aware for many years that if cancer patients are not able to deal with the stress associated with being sick, the cancer will progress faster than in calmer patients. To counteract this phenomenon, physicians encourage treatments that help cancer patients handle their stress. Scientists theorized that the stress relief may have come as a result of increased beta-endorphin peptide (BEP), the "feel good" hormones in the brain that are released during exercise, a good conversation, and many other aspects of life that give humans pleasure.
Researchers at Rutgers hypothesized that BEP producing neurons do not just make us feel good, but also play roles in regulating the stress response and immune functions to control tumor growth and progression. In a paper published recently in the Proceedings of the National Academy of Science, Dr. Dipak K. Sarkar and his colleagues demonstrate the physical mechanisms that support their hypothesis.
http://www.sciencedaily.com/releases/2008/06/080609171202.htm