Featured Study- Depression as a Predictor of Disease Progression and Mortality

Because I am a big believer in the power of the mind and the importance of one’s mood in the fight against cancer, I am starting off this feature with a research study undertaken by Jillian R. Satin, MA, and her colleagues, entitled Depression as a Predictor of Disease Progression and Mortality in Cancer Patients: A Meta-Analysis (the “Satin Study”).   It was published in Cancer 115, no. 22, pp. 5349-5361 (Nov. 15, 2009), and is available here.

The Satin Study is a “meta-analysis.”  What this means is that it looks at and analyzes the results found in several other, previously done studies.  In fact, Dr. Satin and her colleagues analyzed more than thirty studies evaluating the effect of depression on the mortality rates of several thousand cancer patients.  The researchers noted, based on their review, that “[e]ighty-five percent of cancer patients and 71.4% of oncologists endorse the belief that psychological variables affect cancer progression.”  Id. at 5349-5350, 5353-5354.  The study indicated further that:

The current meta-analysis presents fairly consistent evidence that depression is a small but significant predictor of mortality in cancer patients.  Estimates were as high as 26% greater mortality rate among patients endorsing depressive symptoms and a 39% higher mortality rate among those diagnosed with major depression.

Id. at 5356.

Although the Satin Study authors noted some limitations in their analysis, they stated that it suggested that “depression may be an independent risk factor in cancer mortality, rather than merely correlating with biological factors associated with a poor prognosis.”  Id.  The biological mechanism they suggested is an activation of the hypothalamopituitary-adrenal axis, which may affect the cellular immune system and thereby increase the potential for tumor growth.  In addition, the authors noted that certain inflammatory molecules that play a role in the immune system can be affected adversely by depression.  Id. at 5350.  In layman’s terms, according to the Satin Study, depression may cause a biological response that inhibits the immune system and allows tumors to grow.  Thus, the study authors’ analysis of the other studies that had been done on this issue suggests that depression by itself may be associated with whether someone survives cancer or not.

Whether mood actually plays a role in any particular patient’s success in battling cancer is an issue that continues to be debated.  However, many cancer patients and survivors – me included – believe that it does.  The fact is that there are cancer patients of similar age and overall peripheral health, who suffer from the same type and stage of cancer, yet some of those people survive their cancers and others do not.  Perhaps what makes the difference is mood and attitude.  At a minimum, working to control and manage depressive feelings during treatment and maintaining a positive attitude about what you are trying to achieve can help keep you on your track and lead you to follow closely your treatment protocol, even if it is difficult to do so.  It also will make those around you feel more at ease as they fight this battle at your side.

Let me know what you think.  In healing,

Howard

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