Jul 07, 2014
By Shira Klapper, Senior Writer/Editor
Researchers have long known that demographic factors such as age, race, and income have an impact on the health outcomes of men with prostate cancer. However, little is known about how another factor—depression—affects the course of the disease. Now, a new study in the Journal of Clinical Oncology focuses on that specific mental health characteristic. The study, “The Effect of Depression on the Diagnosis, Treatment and Mortality of Men with Clinically Localized Prostate Cancer,” found that men with clinically localized prostate cancer who had been diagnosed with depression in the last two years had a significantly higher risk of being diagnosed at a later stage, received less than optimal treatment, and survived for a shorter time, compared to men with the same cancer diagnosis who did not have depression.
This JCO study, published online, ahead of print, July 7th, is the first of its kind to look at how depression may lead to negative health outcomes among men with prostate cancer. Previous studies have also looked at the intersection of depression and prostate cancer, but from the reverse perspective, in terms of how the negative health outcomes of the disease may lead to depression.
Jim Hu, MD, MPH, a co-author on the study, stated that the findings are part of a larger body of research showing that depression negatively affects health outcomes in numerous diseases.
Jim Hu, MD, MPH
“There has been some research in other disease processes like breast cancer and hepato-biliary cancer where investigators have found that depression has been associated with worse outcomes and the same is true in other, non-cancer areas like hip fractures or strokes or heart disease,” said Dr. Hu. “And so we wanted to determine if the association is also seen in two relatively common conditions in elderly American men—depression and prostate cancer—in terms of the effects on treatment choices as well as survival.”
Analyzing depression’s effect on prostate cancer outcomes
To assess whether depression has an effect on the diagnosis, treatment, and outcomes among men with prostate cancer, the study used the Surveillance, Epidemiology and End Results (SEER)–Medicare linked data to look at 41,275 men who had been diagnosed with localized prostate cancer between 2004 and 2007. The study then separated out 1,894 of those men who had been diagnosed with depression in the two years prior to their cancer diagnosis. The analysis was then focused on whether the depressed men fared differently from men without depression in terms of three outcomes: stage of their cancer at the time of diagnosis, whether they received modes of treatment that follow current guidelines, and their rates of mortality.
The study found that among the 41,275 men with prostate cancer, those with a diagnosis of depression were more likely to be diagnosed with high-risk disease. The study also found that men with depression were less likely to receive optimal treatment and that they were more likely to die sooner than men without depression.
Depression and disparities in care
In terms of medical treatment, Dr. Hu explained that men with depression were significantly more likely to receive expectant management for low, intermediate, and high-risk disease rather than definitive therapy, which is the therapy endorsed by guidelines.
“Definitive therapy is any attempt to actually cure the prostate cancer,” said Dr. Hu. “What falls into the category of definitive therapy is surgery or radical prostatectomy to remove the prostate cancer or radiation therapy of the prostate. Depressed men were less likely to get radiation or surgery, which is against the guidelines for intermediate and high-risk disease.”
“They were more likely to get expectant management, which is either androgen-deprivation therapy, where you give someone hormones to decrease the aggressiveness of prostate cancer or they did nothing at all, which is called ‘watchful waiting’ or active surveillance.”
Ultimately, trying to tease out the connection between depression and negative health effects is a knotty endeavor; it’s difficult to know whether the observed health effects are due to external causes or to the nature of depression itself. For example, it could be that many doctors have preconceived notions about patients with mental illness, causing them to recommend less aggressive treatment. However, it could be that the negative health outcomes are due to changes in body chemistry that accompany depression and that may make patients more vulnerable to the cancer’s effects.
“We know that, just on a biologic level, depressed men have endocrinologic differences in hormone-levels that might have an impact on overall survival,” said Dr. Hu.
In addition to the biologic changes that attend depression, there are also behavioral changes that might result in negative health outcomes, specifically, a depressed patient’s choice of treatment. After all, depression often handicaps people’s ability to invest in behaviors that will enhance their well-being.
“The depressed patient might have a general lack of initiative to follow through with whatever the doctor’s recommendations are,” explained Dr. Hu.
A call for greater screening
It is possible, however, that yet another factor might explain the greater number of negative health outcomes seen in patients with depression—and it lies in a paradox uncovered by the study’s analysis.
“Counter-intuitively, depressed men had a greater number of doctors’ visits and yet were more likely to be diagnosed with high-risk or more aggressive prostate cancer,” said Dr. Hu. One possible explanation for this paradox is that while doctors are often seeing these patients who have depression, they are not discussing the importance of or guiding patients towards prostate cancer screening. “Maybe doctors are not bringing up the issue of screening because, among all the issues these patients present with, that issue is lower on the totem pole,” said Dr. Hu.
Another reason may be that men with depression are biologically at greater risk of aggressive prostate cancer.
According to Dr. Hu and his co-authors, this study might be a call for fostering greater awareness among doctors about the importance of identifying depressed patients and speaking with them about prostate cancer screening.
“It appears that as doctors we need to be more cognizant that patients with depression may be harboring aggressive prostate cancer,” said Dr. Hu. “And we need to talk to them about the benefits of doing a prostate cancer screening test to try to catch these prostate cancers earlier when they’re more treatable.”
Jim C. Hu, MD, MPH, is the Director and Henry Singleton Chair in Robotic and Minimally Invasive Surgery, Co-Director of the UCLA Center for Advanced Surgical and Interventional Technology, and Director of the Urology Procedures Unit at UCLA.
Click here to read the abstract.
Click here to read the PDF.
Prasad, SM, Eggener, SE, Lipsitz, SR, et al. The effect of depression on the diagnosis, treatment and mortality of men with clinically localized prostate cancer. J Clin Oncol. 2014. Published online ahead of print 7.7.2014.
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@ 2014 American Society of Clinical Oncology