DDNews Cancer Research Exclusive: Exploring the link between depression and cancer
LOS ANGELES—A recent University of California, Los Angeles (UCLA) study has found that men suffering from depression and localized prostate cancer are more likely to be diagnosed with aggressive prostate cancer, receive less effective treatments and have shorter survival times than prostate cancer patients who are not depressed.
The results come from a population-based observational study utilizing patients from the Surveillance, Epidemiology and End Results (SEER) Medicare database. It focused on 41,275 men diagnosed with localized prostate cancer between 2004 and 2007, who were then observed through 2009. Of that number, 1,894 men with a depressive disorder were identified in the two years before their cancer was diagnosed. Dr. Jim Hu, UCLA’s Henry E. Singleton professor of Urology and director of robotic and minimally invasive surgery at the David Geffen School of Medicine at UCLA, was the study’s lead author. The study, “Effect of Depression on Diagnosis, Treatment and Mortality of Men With Clinically Localized Prostate Cancer,” was published July 7 in the early online edition of the Journal of Clinical Oncology, a peer-reviewed journal of the American Society of Clinical Oncology.
Next to skin cancer, prostate cancer is the most frequently diagnosed cancer in men; it is forecast that some 233,000 new cases will be diagnosed this year, and of those, nearly 30,000 men will die of the disease.
According to Hu, there could be a number of factors behind the connection between depression and poor outcomes for prostate cancer patients, such as bias against mental illness or depression leading to a lack of interest in health and involved treatments. The biological impacts of depression could be at fault too; Hu says that while it is known that “depressed men have endocrinologic differences in hormone levels that may have an impact on overall survival,” it’s not clear how it affects the aggressiveness of their cancer or their overall survival. Depression has been linked to an increased likelihood of not getting the best treatment and lower overall survival in other cancers, though the extent of its effects are unclear, he added. In the same vein, not much is known with regards to how depression affects diagnosis, treatment and outcomes for prostate cancer patients.
“Men with intermediate- or high-risk prostate cancer and a recent diagnosis of depression are less likely to undergo definitive treatment and experience worse overall survival,” Hu said. “The effect of depressive disorders on prostate cancer treatment and survivorship warrants further study, because both conditions are relatively common in men in the United States.”
Other results from the study included that men who are depressed are less likely to pursue surgery or radiation as treatment; instead, says Hu, “we found that they were more likely to seek androgen-deprivation therapy (hormone therapy), which has increasingly been called into question in terms of improving survival in non-metastatic prostate cancer and may actually contribute to diabetes, heart disease and worsen mental health.”
Their decision to forego surgery or radiation is surprising, Hu noted, “because depressed men were more likely to see physicians in the two years prior to prostate cancer diagnosis compared to non-depressed men.”
“We need to tease out the degree to which biologic, patient and/or health care provider factors are contributing to: (1) the more aggressive prostate cancer found in depressed men at the time of diagnosis; (2) the worse survival of depressed prostate cancer patients,” says Hu.
“Our study findings provide a firm foundation to prospectively explore the affect of depression on prostate cancer survivorship through focus groups and community-based, population studies,” he concludes.