Psychological stress and cancer

Psychological or psychosocial stress has been emerging as one of the key factors associated with cancer initiation, growth, and metastasis. Accumulating data, however, has mainly focused on cancer progression due to the inconsistent results of cancer etiology caused by emotional stress. Depression is closely linked to stress and induces hypothalamic-pituitary-adrenal (HPA) axis activation as well as sympathetic nervous system (SNS) down to immune cell surveillance. This review briefly describes the activation of neuroendocrine system by psychological stress/depression and its effect on cancer occurrence and metastasis, which may be useful for the design of new cancer treatments.