Final Project Annotated Bibliography
Contrada, Richard, and Andrew Baum. The Handbook of Stress Science: Biology,
Psychology, and Health. Springer, 2011. Print.
The handbook covers in great detail the biological and psychological effects of stress in humans and compiles the work of scientists and researchers who improved on the concepts and theories of Hans Selye. And although Selye accurately identified the key parts of the body that are affected by stress, scientists referenced in the handbook have taken his research more than a step further to actually understand the factors behind the correlations. The debate over how strictly to follow definitions of stress is briefly mentioned and suggests opposing theories between earlier and later interpretations of the term itself. Other concepts introduced include stress networks and the importance of glucocorticoids.
More importantly, the handbook covers several of the implications stress has on overall health. Health complications that can arise from excessive stress include: changes in eating behavior, increases in drug use, worsened complications during pregnancy, depression and other mental health problems, physical trauma, cardiometabolic syndrome, cancer, susceptibility to infectious disease, worsened complications in HIV/AIDS, and other physical aches and pains. Great detail is given in support of other research I read on the relationship between stress, cancer/tumor-induction, and complications in HIV/AIDS. Stress affects human health in three general ways: “direct effects on physiological process, behavioral changes that affect physiology…, or changes in behavior.” The key piece I will choose to focus on in this admittedly broad source is the relationship between stress and cancer, although it is possible that some of the other side-effects mentioned can also relate indirectly.
Mackenzie, Robertson. “Targeted Deep Sequencing of Mucinous Ovarian Tumors
Reveals Multiple Overlapping RAS-Pathway Activating Mutations in
Borderline and Cancerous Neoplasms.” 15.415 (2015). BMC Cancer.
Web. 4 Nov. 2015. <http://www.biomedcentral.com/1471-2407/15/415>.
Selected source on ovarian tumors to make identifying similarities/differences in tumor research easier (I’m still learning about this topic), however I will not necessarily focus primarily on ovarian cancer. This source focuses on the sequencing of “50 genes commonly mutated in human cancer across 69 mucinous ovarian tumors.” Many tumors that were thought to be “RAS-pathway alternation negative” actually aren’t, and this topic is also discussed by Myrthala Moreno-Smith’s Impact of Stress on Cancer Metastasis. Using highly-sensitive sequencing has enabled the researchers to explore heterogeneity in “RAS-pathway activating alternations.”
Among the muscinous borderline tumors studied, KRAS mutations were the most frequently observed alternation by 92.3 percent. The “prevalence of RAS-alternation and striking co-occurrence of pathway ‘double-hits’ supports a critical role for tumor progression…” This source explores the technicalities (mentioned above) of mutations and cancerous tumors. Although specific to ovarian tumors, the research here can be generalized and used in reaching other conclusions.
Moreno-Smith, Myrthala. “Impact of Stress on Cancer Metastasis.” Future Oncol 6.12
(2010): 1863-881. PMC. Web. 3 Nov. 2015. <http://www.ncbi.nlm.nih.gov/pmc/
This source realizes Stress Science is still a relatively new field and admits there has been “only limited evidence for the role of these behavioral factors in cancer initiation.” For the past 30 years, we’ve instead relied on epidemiological and clinical studies for evidence of links “between chronic stress, depression…, and cancer progression.” Recent studies, however, break this trend and actually introduce a new theory behind the complex relationship “between psychosocial factors, specifically chronic stress, and cancer progression.”
The “strongest links to cancer to progression” are not stressful events, but prolonged exposure to moods of depression or hopelessness. In fact, many studies link strong social support with improved prognoses – and even greater chance of survival – in cancer patients. The studies add to the conclusions of Seyle by confirming not only that the nervous system (and hormonal system) plays a key role, but that the release of dopamine in the brain during high-stress situations is a contributing factor. Neuroendocrine mediators control cellular function in areas where cancer is most likely to begin and progress. In the ovary, for example, catecholamine levels are increased in response to stress to the degree of actually causing the formation of precystic follicles. The source aligns with Richard Contrada’s research in The Handbook of Stress Science: Biology, Psychology, and Health by placing high importance on the study of glucocorticoids, or “a class of steroid hormones that bind to the GC receptor.” GC receptors are partially responsible for modulating “immune activity and inflammatory responses.” How to tumors actually develop? To better understand the discussions of this source, it is helpful to research the science behind cancerous tumors themselves (see research conducted by Robertson Mackenzie).
Selye, Hans. The Stress of Life. New York: McGraw-Hill, 1956. Print.
This physician is widely considered the “father of stress,” as he coined the term through experimenting with lab rats in the mid-twentieth century. In his experiments with rats, he injected them with harmful substances in specific organs and studied how the rats reacted. What he found, however, was not what he expected; the rats did not demonstrate symptoms that should occur when a particular organ temporary functioned at a reduced efficiency. In other words, the rats reacted instinctively in a way different from what the side-effects should have caused. These reactions were based on a psychological response that in turn led to other biological reactions.
Selye called this response the General Adaptation Syndrome, which is made up of three stages: “1) the alarm reaction, 2) the stage of resistance, and 3) the stage of exhaustion.” He measured both positive and negative stress as the “totality” of changes observed to have taken place during General Adaptation Syndrome. Selye determined the adrenal glands, thymus, a group of three lymph nodes, and the inner surface of the stomach to be the biological factors most heavily affected by the syndrome. Although the technology available to Selye during his time was relatively rudimentary, he established the basis though which stress would be studied throughout the rest of the twentieth and twenty-first centuries with his legacy of empiric research. The experiments Selye conducted work as a starting point for my research and point me in the right direction for deeper research.
Sudhakaran, Perumana. Perspectives in Cancer Prevention – Translational Cancer
Research. New Delhi: Springer, 2014. Print.
This source both contradicts and confirms my previous research. Contradictory to Moreno-Smith’s Impact of Stress on Cancer Metastasis, and “contrary to community beliefs, there has been no evident association between stress and… cancer risk in large prospective cohort studies” (156). Through this perspective, stress is “thought to be more influential in the progression and recurrence of cancer than its initial onset.” Sources referenced here, however, date back to the late-1990s and early-2000s, so room is of course left for these statements to be refuted appropriately.
“Experimental research in animals… has found that stress contributes to the initiation, growth, and metastasis of select tumors.” In humans, stress has been shown to affect “key pathogenic processes in cancer, such as antiviral defenses, DNA repair, and cellular aging.” Sudhakaran points out that one study found strong evidence that “those whose mental health had suffered due to the stress of the Chinese social revolution” showed greater instances of cancer than others. Sudhakaran values the study techniques but criticizes it as relying on correlation instead on actual causation. A theory of work stress in relation to cancer is also introduced: with a rise in workplace stress over the past 40 years, we should also see a rise in number of cancer diagnoses, and that workers in highly developed countries where workplace stress is often higher should be of higher risk for the disease. “Nearly 70 percent of the cancer deaths occur in low and middle income countries,” however, suggesting the theory is inaccurate. What is the actual relationship between stress and the introduction of a cancerous tumor? Sources unanimously confirm the significance of stress with relation to tumor progression, but not the introduction.