Is Loneliness Bad for Cancer Growth?

Although researchers have generally discredited the notion of specific cancer-prone personalities, intriguing links continue to suggest that features of psychological life affect the course of malignancies. Previous work suggested that gynecological cancer patients with higher levels of social attachment and support have lower levels of two proangiogenic cytokines — vascular endothelial growth factor (VEGF), a tumor-growth–promoting factor; and interleukin (IL)-6. These researchers assessed implicit and explicit loneliness in 51 newly diagnosed patients with colorectal tumors (mean age, 68) and used immunohistochemical assays to determine expression of the two cytokines in tumor tissue taken during surgery 1 to 2 days later.

Patient-rated scales of explicit loneliness assessed negative feelings related to low social support. Implicit loneliness was measured via a timed computer-based test assessing participants' identification with abandonment and isolation; the authors stated that this test validly reflects these socially sensitive constructs. (Ratings of implicit and explicit loneliness showed no correlations.)

After controlling for cancer stage, age, and explicit loneliness ratings, which were insignificant predictors, researchers found that higher implicit loneliness ratings were associated with stronger VEGF expression. IL-6 levels were not associated with either implicit or explicit loneliness ratings.