Stress and Cancer

Norepinephrine, a hormone produced during periods of stress, may increase the growth rate of cancer.
The norepinephrine can stimulate tumor cells to produce two compounds (matrix metalloproteinases called MMP-2 and MMP-9) that break down the tissue around the tumor cells and allow the cells to more easily move into the bloodstream.
Once there, they can travel to other organs and tissues and form additional tumors, a process called metastasis.
Norepinephrine may also stimulate the tumor cells to release a chemical (vascular endothelial growth factor, or VEGF) that can aid in the growth of the blood vessels that feed cancer cells. This can increase the growth and spread of the cancer.
Researchers traced the harmful effect of norepinephrine after applying it to cancer cell lines used to study nasopharyngeal carcinoma (NPC), an incurable head and neck cancer associated most frequently with those of Chinese descent.
Cancer Research November 1, 2006; 66(21): 10357-10364
Science Daily November 3, 2006