I Cannot Hide My Surprise: Apparently Stress Does Not Cause Cancer!

Science sometimes makes us say, “Surely not, that is too much!” Sometimes we combine what suits us with a few scientific crumbs and create conventional truths. Years later, when scientific data begin disproving conclusions we accepted as true, we can be surprised.

“My spouse upset me so much over the last year that I developed cancer,” “I was very unhappy at work, so I got cancer,” or “My daughter upset me greatly; that is why your treatments did not work, Doctor, and my disease progressed.” As an oncologist, I encounter such statements from patients many times in daily life.

Over the years I have followed scientific literature examining this issue and, as an individual too, tried to find data supporting these statements. We always carry the idea that sadness from life's difficulties weakens our defenses and creates susceptibility to cancer. Although I have read supportive studies, I found them extremely weak and insufficient to clarify this judgment.

I therefore wanted to share results of a new study in the highly respected European Journal of Epidemiology. Contrary to established beliefs, it found no relationship between stress and cancer. It demonstrated that cancer belongs to a group of diseases that cannot simply be explained by personal and social observations.

This research examined relationships between post-traumatic stress disorder (a psychological disorder caused by extreme anxiety, concern and stress after a traumatic event) and various cancers. Considering sex and age distribution, it studied Danish adults diagnosed between 1995-2011 who were older than 16. Following an average 16 years of observation, 4131 adults (% 60 women) were found not to develop cancer during the first year after diagnosis. In subsequent years, cancer incidence was also unrelated to post-traumatic stress disorder. Findings from this large study indicated no connection between post-traumatic stress disorder and many cancer types.

I should note that the study did not examine whether our immune system is related to cancer, and we are not claiming there is no such relationship. The immunity–cancer relationship is a proven mechanism. New treatments in this field are even opening groundbreaking paths in cancer care. This study instead suggests that the influence on cancer formation of problems causing serious stress and sadness in our lives should be almost disregarded.

Dear friends, some earlier studies suggested stress might be associated with cancer. However, these data may change the perception of ‘stress-induced cancer.’

Epidemiology: A branch of medicine studying the distribution and frequency of diseases, accidents and health-related conditions in society, and the factors influencing them.