Is psychological stress a risk factor for the induction and development of tumors?

摘要

abstract_textpThe results of epidemiological studies on the connection between psychological stress (at work or due to traumatic live events) and the induction and development of tumors are still contradictory and characterized by a high degree of variance. In the majority of studies psychological stress increases the risk of certain tumor types, for example the most widely investigated breast cancer. Sub-stages on the path from stress to increased risk of cancer originate from stress-induced addictive behavior (smoking, alcohol consumption, adiposity) and also from the effects of stress hormones and their influence on the immune system. Addictive behavior includes a number of cancer risks, e. g. by increased amounts of reactive oxygen species (ROS) from smoking and alcoholism which are mutagenic and carcinogenic, or increased production of adipokines in fat cells, whereby the proliferation rate of cancer cells can also be stimulated. Stress hormones and pro-inflammatory cytokines increase the risk of chronic inflammation by severe stress, which can then be carcinogenic due to a number of factors. The defense mechanisms of the immune system against cancer cells (immuno-surveillance) are also inhibited by stress. Finally, stress accelerates aging processes such as the shortening of telomeres which have also been shown to be a cancer risk. The influence of psychological stress on cancer induction an development should therefore be taken into consideration for preventative measures as well as for therapy./p/abstract_text