Meta-analysis: Depression independent risk factor for cancer mortality

Depression was associated with risk for mortality but not progression in patients with cancer, according to data from a meta-analysis. Mortality rates were up to 25% higher among patients demonstrating depressive symptoms and 39% higher in those diagnosed with major depression.

Using the Medline, PsycInfo, Cinahl and Embase databases, researchers collected data for 9,417 patients from 26 prospective studies that examined the association between depressive symptoms or major or minor depression and the risk for disease progression or mortality in patients with cancer.

Depressive symptoms did not significantly predict cancer progression (risk ratio=1.23; 95% CI, 0.85-1.77), according to data from three available studies. However, data from 25 independent studies demonstrated that there were higher mortality rates in patients who reported depressive symptoms (RR=1.25; 95% CI, 1.12-1.40) and those diagnosed with major or minor depression (RR=1.39; 95% CI, 1.10-1.89).

There was no evidence that adjusting for known clinical prognostic factors reduced the effects of depression on mortality. According to the researchers, this suggests that depression may be an independent risk factor for cancer mortality.

Based on their results, the researchers made several recommendations, including the measurement of depression at multiple timepoints. The researchers also recommend that cancer-specific and all-cause mortality be reported separately to determine the direct effect of depression on cancer outcome.

“Although psychological treatment should be available to distressed cancer patients for assistance in coping with the burden of a chronic life-threatening illness, an impressive improvement in survival is unlikely unless a subgroup is identified that could benefit more than others,” the researchers wrote.

Satin JR. Cancer. 2009;doi:10.1002/cncr.24561.