– Stress and breast cancer

Stress and breast cancer

Self-reported stress levels predict subsequent breast cancer

Women reporting experience of stress during the five years preceding the first examination displayed a two-fold rate of breast cancer compared with women reporting no stress.

Sympathetic nervous system induces a metastatic switch

Stress-induced neuroendocrine activation had a negligible effect on growth of the primary tumor but induced a 30-fold increase in metastasis to distant tissues including the lymph nodes and lung.

Stress & breast cancer: from epidemiology to molecular biology
An epidemiological overview of the research. While they are basically concluding that more research needs to be done, they offer references to over a 100 studies that you may wish to peruse and offer a great explanation of theories of biological mechanisms.