Okay, I pulled the article. Here are relevent points:
“Stress is associated with increased expression of interleukin 1, interleukin 6, and TNF α released from cells from the macrophage or monocyte lineage, with reduced expression of interleukin 2, interferon γ, and class-II MHC molecules, with down-regulated interleukin 2, and with reduced NK activity. Most organ-related carcinomas are associated with high concentrations of TNF α, which inhibits the activity of tyrosine phosphatase, which in turn results in diminished expression of the class-I MHC antigen on the cell surface, thus permitting malignant cells to escape immune surveillance. Therefore, stress and depression can foster tumour progression by inhibition of the expression of class-I and class-II MHC molecules and by reducing NK activity.”
I pulled that article, and that was basically an opinion piece. So it’s a restatement of an opinion.
“These notions could explain the increased occurrence of lymphatic and haematological malignant diseases, and of melanomas seen in a cohort of 6284 Jewish Israelis who lost an adult son. The incidence of cancer was increased in the parents of accident victims and in war-bereaved parents, compared with that in non-bereaved members of the population. Accident-bereaved parents also had an increased risk of respiratory cancer. Followed up for 20 years, the survival study showed that the risk of death was increased by bereavement if the cancer had been diagnosed before the loss, but not after.[60]”
I didn’t pull this article, but it’s a compelling case-control study.
“After exposure to x-radiation, peripheral blood leucocytes obtained from 28 non-psychotic, non-medicated new psychiatric patients showed greater impairment of DNA repair when compared with 28 age-matched and gender-matched blood-bank controls.”
Only 28 patients, so the power is quite small.
“The relation between stressful life experiences and breast cancer has been the subject of a great deal of research, most of which has been characterised by weak design and contradictory results. A retrospective study[64] did not show any important association between stressful life events and breast cancer. A meta-analysis[65] concluded that the few well-designed studies that have been done did not find evidence of a link. A further observational cohort study[66] also did not confirm that severely stressful life experiences increase the risk of relapse of breast cancer.”
“Conflicting reports on the association between tumour development and psychological stress in both human and animal studies might be explained by the variations in stress chronicity, timing of stress, and types of tumours tested.[31] ”
“Although the published work investigating the involvement of psychosocial factors in cancer cause, progression, or response to treatment is extensive, the most common are studies comparing patients with cancer with those who do not have the disease. These studies could be flawed by the effects of patient’s knowledge of their prognosis. Many of the effects of psychosocial factors are likely to be related to behavioural choices, such as smoking, that are known to affect the risk of cancer. The determination of causal links between psychosocial factors and the incidence of cancer is also obscured by the long delay between the development of malignant disease and the detection of neoplastic disease. Furthermore, the studies have used types and stages of cancer that differ biologically in important ways and therefore could be affected differentially by psychological and immune factors.[68] ”
Okay, I’m willing to give this much. There is a POSSIBLE link between psychological stress and cancer progression. The data are conflicting.