Stress DOES have an impact on cancer

Stress fuels cancer by triggering a 'master switch' gene which allows the disease to spread, according to new research.
The 'unexpected' discovery could lead to the development of drugs that target the protein and stop tumours spreading to other organs and causing death. Stress has long been linked to many forms of the disease including breast and prostate cancer, but the reason has remained a mystery. 
Now a team at Ohio State University say our own bodies help turn cancer against us by turning on a 'master switch' gene known as ATF3 which is expressed in response to stressful conditions in all types of cells. Usually, it causes normal and benign cells to commit suicide if they decide they have been irrevocably damaged.
But cancer cells somehow coax immune-system cells recruited to the site of a tumour to express ATF3. It is unclear exactly how, but the gene promotes the immune cells to act erratically and give cancer an escape route to other areas of the body.

Source  - Daily Mail