Associations between plasma cytokines and depressive mood in patients with breast cancer

The few studies on the associations between cytokines and depressive mood in patients with cancer have produced conflicting results. This study investigated the associations between plasma cytokines and depressive mood in patients with breast cancer using a large panel of pro-inflammatory, anti-inflammatory, and immune-modulating cytokines.

We recruited 273 hospitalized patients with breast cancer awaiting surgery. Preoperative plasma samples were obtained for cytokine analysis, including pro-inflammatory (interleukin [IL]-2, IL-12, interferon [IFN]-gamma, and tumor necrosis factor [TNF-alpha]), anti-inflammatory (IL-4, IL-5, IL-10, and IL-13), and immune-modulating (granulocyte/macrophage colony-stimulating factor [GM-CSF]) cytokines. Depressive mood was measured using the Montgomery-Asberg Depression Rating Scale (MADRS) at 2-5 days postoperatively, when the patients could cooperate. Covariates included various demographic and clinical characteristics. The association between the MADRS score and each cytokine level was estimated using linear regression models.

Cytokine levels were significantly inter-correlated. Depressive mood was associated with lower levels of pro-inflammatory (IL-2, IL-12, and TNF-alpha), anti-inflammatory (IL-5, IL-10, and IL-13), and immune-modulating (GM-CSF) cytokines independent of potential covariates such as living area or functional level.

The findings suggest that depressive mood is associated with a generally decreased inflammatory reaction or immune function in patients with breast cancer.