Stress Linked to Cancer

Scientists have discovered that everyday emotional stress is a trigger for the growth of tumors. Any sort of trauma, emotional or physical, can act as a "pathway" between cancerous mutations, bringing them together in a potentially deadly mix.
The findings seem to show for the first time that the conditions for developing the disease can be affected by your emotional environment, including everyday work and family stress.
Until now, scientists believed more than one cancer causing mutation needed to take place in a single cell in order for tumors to grow.
But researcher showed that mutations can promote cancer even when they are located in different cells, because stress opens up "pathways" between them.
The study by Yale Univesity researchrs found that stress, even the normal everyday variety, can act as a pathway between cancerous mutation, potentially triggering the growth of tumors.
The National Cancer Institute has said that research with animal models suggests that "your body's neuroendocrine response (release of hormones into your blood in response to stimulation of your nervous system) can directly alter important processes in cells that help protect against the formation of cancer, such as DNA repair or the regulation of cell growth."
Other research has shown that norepinephrine, a hormone produced during periods of stress, may INCREASE THE GROWTH RATE OF CANCER.
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 your bloodstream.
Once there, they can travel to other organs and tissues and form additonal 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.
The stress hormone epinephrine has also been found to cause changes in prostate and breast cancer cells in way that may make them resistant to cell death. This means that emotional stress could both CONTRIBUTE TO THE DEVELOPMENT OF CANCER AND REDUCE THE EFFECTIVENESS OF TREATMENTS.