According to a report and survey published in Psychooncology a substantial part of women who had survived breast cancer believe that there is a link between breast cancer and psychological stress.
In this report, Stewart DE et al., from the University Health Network Women’s Health Program, University of Toronto, Canada surveyed 378 women breast cancer survivors about their views on the cause and lack of recurrence of their breast cancer.
Interestingly, women who responded to the question about the cause of breast cancer attributed it mostly to stress (42.2%), genetics (26.7%), environment (25.5%) and hormones (23.9%).
Thus, the majority (42%) believed stress was one of the main causes of their disease.
Despite the high profile of families with a genetic link in recent years, only 27% thought genetics was a factor, with almost the same number suggesting environmental factors had played a part in causing their cancer.
According to a BBC news report (see below), Dr. Donna Stewart, who led the study, said the belief that stress had caused their disease, and lifestyle changes following it could help women feel they had control over the condition.
A 2014 systematic reviewincluded 22 studies that met the inclusion criteria. Results indicated a consistent belief among survivors that their own breast cancer could be attributed to family history, environmental factors, stress, fate, or chance.
The authors ofa 2018 studytried to assess the risk factors for breast cancer from the point of view of survivors. These authors ran a survey with open- and closed-ended questionnaires on patients’ opinions about risks factors both for women in general and for their own case. Of note, most patients had no opinion, but for the rest, most frequently cited risk factors were stress, then genetic causes, and poor diet.
Another 2018 aimed to understand how stressfulness appraisal of salient Life Events (LEs) influences breast cancer risk. The study included 664 female cases identified through the Cancer Surveillance Program of Orange County, CA. The results indicated that the cumulative adverse LEs perceived as stressful were associated with increased breast cancer risk in a dose response fashion. Of note, pre/peri-menopausal women who were nulliparous or who had their first child at ≥30 years of age were especially prone to the effects of appraised stress on increased breast cancer risk.
The authors of this study concluded that their results suggest that LEs differentially influence breast cancer risk according to stress perception. This is consistent with previous research highlighting the importance of stress appraisal in altering the physiological stress system.
Importantly, these authors found that negative valence LEs were those to have the greatest likelihood of being perceived as “stressful”. Therefore, negative valence, cumulative LEs perceived as stressful seem to be most influential in increasing breast cancer risk.
Furthermore, a history of personal illness, defined as ‘serious illness or injury of oneself’ was significantly associated with increased breast cancer risk both when perceived as stressful and when perceived as non-stressful. Of note, these results are in line with a previous study by Helgesson et al. where perceived stress was associated with an approximately 2-fold increase in breast cancer risk.
A 2022 systematic review indicates that, in addition to the known risk factors, psychological factors may play an important role in the aetiology of both breast and lung cancer. According to the authors of this study, in 2020 breast cancer had the highest number of new cases, and lung cancer was second in number of new cases and the first in number of deaths.
This review demonstrated that some adverse life events/trauma are statistically associated to an increased risk of breast cancer. In particular, the self-reported events perceived at baseline with psychological distress stand out, such as the death of a friend, close family member, or spouse. Death as an adverse life event/trauma seems to contribute the most to breast tumor development. Therefore, psychological treatment of adverse life events/trauma can reduce the occurrence of breast cancer in females.
Another question reviewed was the existence of an association between depression and breast cancer risk. Previous work indicates that depression was the most studied psychological factor, being associated with a small to moderate breast cancer risk in females.
Thus, these results support the evidence already described in the literature, that depression is a factor to be considered in the subsequent development of overall cancer. However, 15 of the 20 studies included in this systematic review did not support this relationship.
The authors concluded that the psychological factors in cancer should be considered and deserve further investigation. Importantly, to consider psychological factors as a variable that affects cancer development may be fundamental to opening new avenues for prevention and intervention.