Background: Relations among psychological stress, depression, social support, and interleukin-6 (IL-6, a proinflammatory cytokine) have been documented in humans and animals. Because elevated IL-6 is associated with a poorer prognosis among ovarian cancer patients and has been implicated in the metastasis of ovarian cancer, the current study examined relations between psychosocial factors and IL-6 among women with advanced-stage ovarian cancer.
Methods: Sixty-one ovarian cancer patients completed assessments of social support, distressed mood, and quality of life before surgery. Peripheral blood was drawn preoperatively, and the plasma was assayed for IL-6. Ascites samples were also assayed for IL-6 for a subset of patients.
Results: Both IL-6 levels and distressed mood were elevated among patients. After statistically adjusting effects of age and disease stage, social attachment was associated with lower levels of IL-6 in peripheral blood (P = 0.03), whereas poorer health-related quality of life was associated with higher IL-6 (P values ranged from 0.01 to 0.03 on different measures). This pattern of relations was also found in the ascites. Moreover, IL-6 levels in peripheral blood plasma correlated significantly with IL-6 in the ascites (P < 0.001), suggesting that peripheral IL-6 reflects IL-6 levels at the site of the tumor.
Conclusions: Results suggest that social support may play a protective role with respect to IL-6 elevations, and IL-6 may be an independent marker of health-related quality of life among ovarian cancer patients. Processes involving IL-6 represent possible pathways by which behavioral factors may contribute to disease outcomes among women with ovarian cancer.