Impact of Stress Upon Cancer Metastasis, 2010, Moreno-Smith et al

I haven't read this paper yet, just the abstract. The role of cortisol in cancers is something I've been giving some thought to, after a friend said that he thought the stressful job he had when he first became ill might have caused his leukemia.

The title of the following 2018 paper appears at first glance to suggest there might be something in that idea:
Cortisol facilitates the immune escape of human acute myeloid leukemia cells by inducing latrophilin 1 expression, 2018
However, it turns out that this paper isn't evidence that stress or even cortisol causes cancer. It suggests that you have to have the acute myeloid leukaemia cells first, and they use cortisol to induce expression of a receptor that causes some effects that favour the survival of the malignant cells.

It's not so much that 'cortisol causes the cancer'. It seems to be more that leukemia cells increase cortisol levels.
(Leukemia cells cause reduced blood glucose levels > increased CTRH > increased ACTH > increased cortisol)
In the presence of the leukaemia cells, the cortisol up regulates LPHN1, and LPHN1 interacts with FLRT3 to produce galectin-9. And the galectin-9 protects the leukaemia cells from destruction by immune cells.

There seem to be a few links in the chain of events that don't happen if the leukaemia cells aren't there. Cortisol doesn't cause the problems if the leukaemia cells aren't there.

As the authors of the 2018 paper say:

That's something I think we have to remember. Everyone has cortisol, pretty much everyone has stress. Not everyone gets leukaemia.
And higher levels of cortisol once you have cancer don't necessarily mean you are a high-stress person causing the progression of your cancer - the cancer can increase the level of cortisol. The causality seems to be in the opposite direction from the prevailing view of stress causing cancer.


I don't want to rule out the possibility that someone who is very stressed might have a higher chance of becoming ill. Every gardener knows how plants stressed by a lack of water are far more likely to suffer from diseases than plants that are well-watered and well-nourished. And a stressed person might not sleep well, might not eat well, might smoke and drink alcohol. Being very stressed typically isn't fun, and so ideally we'd organise society so people aren't chronically very stressed.

The 2010 paper that is the subject of the thread notes that there isn't much evidence of the behavioural factors of stress, depression and isolation initiating cancers. I actually think that they could do, but mainly via things like smoking, alcohol, bad food and poor sleep.

The 2010 paper seems to be suggesting that there is strong evidence that stress favours cancer progression. I feel quite doubtful that there is some magical BPS link. I think it's more likely to be mostly the mundane and obvious links - things like people who are isolated not having the support structures to get them to their chemotherapy treatments.

As has been mentioned in other threads with respect to ME/CFS, there's a big problem when people start saying patients have caused their disease, or have failed to beat it, because of their neurotic personalities. Or when it's suggested that people can be fixed by doing a mindfulness course and thinking happy thoughts. I don't think we've seen good evidence for those things in cancer at all.