Stress and cancer – Is there a connection?

Does long term stress cause cancer?

When the body experiences stress it releases stress hormones which increase blood pressure, heart rate and blood sugar levels, in a flight-or-fight response. This is beneficial in momentary stress but can be harmful when chronic. 

Research has shown that people who experience chronic stress can have digestive problems, heart disease, high blood pressure and a weakened immune system (Ayling et al., 2022). But there are few studies directly linking stress and cancer. One case-control study in Canadian men found an association between stress and risk of prostate cancer but a similar study did not find such a link (Blanc-Lapierre et al., 2017; Blanc-Lapierre et al., 2017a). There is some evidence from laboratory studies in animals suggesting that chronic stress may cause cancer to get worse or spread. One study showed that when mice with human tumours were kept in isolation, which increases stress, their tumours were more likely to grow (Moreno-Smith et al., 2017; Sloan et al., 2010). 

Stress can also result in poor lifestyle changes and bad habits such as smoking, alcohol consumption and poor diet all of which are associated with increased risk of cancer. 

Can stress cause cancer cells to grow?

There is no conclusive evidence that stress causes cancer cells to grow. After cancer treatment sometimes some cancer cells remain dormant in the body, these can be difficult to detect. A new study suggests that stress hormones can wake up dormant cancer cells, prompting them to divide into tumours (Perego et al., 2020). There could be several other triggers for this, not just stress. While there is research that has shown a link between stress and cancer in mice there has been no confirmation in people as there are several issues with measuring and defining stress.

Can stress trigger tumours/Can stress cause brain tumours?

There is no current conclusive evidence that stress triggers tumours to grow.

How does stress affect cancer? 

Chronic stress may also lead to the release of certain hormones such as glucocorticoids which are steroid hormones. These may inhibit a type of tumour cell death, increase growth of the cancer, and resistance to chemotherapy as well as prevent the body’s immune system from recognising and destroying cancer cells (15). 

Stress can also have an indirect effect on cancer through the lifestyle changes and bad habits that result from stress. When people are under stress they are more likely to smoke, increase alcohol consumption and have a poorer diet which all increase cancer risk.

Does stress affect cancer recovery?/Does stress affect chemotherapy?

Chronic stress may also lead to the release of certain hormones such as glucocorticoids which are steroid hormones. These may inhibit a type of tumour cell death, increase growth of the cancer, and resistance to chemotherapy as well as prevent the body’s immune system from recognising and destroying cancer cells (15). 

Resources:

Ayling K, Jia R, Coupland C, et al. Psychological predictors of self-reported COVID-19 outcomes: Results from a prospective cohort study. Annals of Behavioral Medicine 2022; 56(5):484–497

Blanc-Lapierre A, Rousseau M-C, Weiss D, et al. Lifetime report of perceived stress at work and cancer among men: A case–control study in Montreal, Canada. Preventive Medicine 2017; 96:28–35. [PubMed Abstract]

Blanc-Lapierre A, Rousseau M-C, Parent M-E. Perceived workplace stress is associated with an increased risk of prostate cancer before age 65. Frontiers in Oncology 2017a; 7:269.

Moreno-Smith M, Lutgendorf SK, Sood AK. Impact of stress on cancer metastasis. Future Oncology 2010; 6(12):1863–1881.

Sloan EK, Priceman SJ, Cox BF, et al. The sympathetic nervous system induces a metastatic switch in primary breast cancer. Cancer Research 2010; 70(18):7042–7052.

Perego, M., Tyurin, V. A., Tyurina, Y. Y., Yellets, J., Nacarelli, T., Lin, C., Nefedova, Y., Kossenkov, A., Liu, Q., Sreedhar, S., Pass, H., Roth, J., Vogl, T., Feldser, D., Zhang, R., Kagan, V. E., & Gabrilovich, D. I. (2020). Reactivation of dormant tumor cells by modified lipids derived from stress-activated neutrophils. Science Translational Medicine, 12(572). https://doi.org/10.1126/scitranslmed.abb5817