Cancer and stress
In recent times thoughts on a link between stress and cancer are once again under serious review. The most important reason that led to a new review was the discovery in 1982 of a link between Helicobacter Pylori and peptic ulcer. With this discovery one of the significant examples for a link between stress and a physical illness was disproven. In 2005 it brought the Nobel price to the scientists (Barry J Marshall, J Robin Warren) who made the discovery. In the speech of the Nobel price it was emphasized that these two scientists had destroyed a dogma. (http://nobelprize.org/medicine/laureates/2005/press.html).
Is it possible that the link between stress and cancer is also a dogma?
The subject should be approached from two angles. Firstly, stress as an aetiological factor that can cause cancer, and secondly stress as a factor that can lead to relapse and shorten average life expectancy. For many years it was claimed that stress plays a secondary role in the emergence of the illness. In other words, although the illness has a genetic base, stress plays a secondary role in triggering this genetic process. It was also observed that the average life expectancy after the emergence of the illness is shorter in people who suffer from stress.
It is extremely difficult to answer the question whether there is a link between stress and cancer. There are two reasons for this difficulty: Even in animal studies it seems impossible to isolate the stress factor. Although it may look as if the application of acute or chronic stress, of stressors like removal from a social environment may cause cancer, there are so many systems that get affected, including the endocrine and immune systems, that when stress is applied it is not possible to isolate it and say “this is the cause!” Human studies are even more complex. One of the best-known genetic theories on the link between stress and cancer was a research carried out in 1985 in which it was claimed that stress damages the DNA structure. The research revealed that stress interferes with the DNA’s ability to repair itself. The research was undertaken by Psychologist Janet Glaser and Virologist Ron Glaser. The inability of the DNA to repair itself occurs in the early stages of cancer. However, for this conclusion to be convincing, research has to be done that covers long periods of time and analyses a large number of cases. (Azar B: Probing links between stress, cancer; APA Monitor Online, 30 (6), 1999).
During a certain period of time the number of research studies conducted on the effects of stress on life span showed an exciting rise. In 1989 David Spiegel, Joan Bloom, Helena Kraemer and Ellen Gotteil published a paper in the reputable medical magazine ‘The Lancet’ (14 volumes, pgs 888-891) which attracted wide attention. The heading of the paper was “Effect of Psychosocial Treatment on Survival of Patients With Metastatic Breast Cancer”. They concluded that reducing stress by psychotherapeutical means plays a positive role in reducing the risk of metastases in cancer patients and improving their life expectancy. However, 12 years later this finding was rejected by another reputable magazine. It was a multi-research publication with Pamela Goldwin as the main researcher, the magazine was ‘The New England Journal of Medicine’ (volume 345, 2001, pgs 1719-26). Goldwin had not arrived at the result Spiegel had arrived at, and claimed that a fault in the method of analysis had caused an error in the previous research.
Based on my personal experience I can say the following: Almost every cancer patient that I have looked after until now has mentioned the presence of a stress factor in their lives at the time of appearance of the disease. As however there are many people who are exposed to the same stress factors but do not develop cancer, I cannot make an interpretation on the basis of the information I received from the patients. With regards to the research studies, the presence of contradicting findings that reject one another shows that there is a problem with the lack of a serious research model and research standards. Add to this the difficulty of isolating stress and it becomes even more apparent why it is so difficult to get at the truth.
In my opinion the main danger after the discovery of H. Pylori is the possibility of a total rejection of a link between stress and cancer, labelling it a dogma, and diminished scientific interest in the subject.
Based on the information and experience at hand we can arrive at the following conclusion: Stress alone is not an active factor (at least not in the majority of cases). However, it would not be wrong to regard stress as one of the important triggers of the carcinogenic process.