Caregiver burden and risk of epithelial ovarian cancer in the Nurses' Health Studies.

Psychosocial stress may increase ovarian cancer risk and accelerate disease progression. We examined the association between caregiver burden, a common stressor, and risk of epithelial ovarian cancer. We prospectively followed 67 724 women in the Nurses' Health Study (1992-2012) and 70 720 women in the Nurses' Health Study II (2001-2009) who answered questions on informal caregiving (ie, caregiving outside of work). Women who reported no informal caregiving were considered noncaregivers, while, among women who provided care outside of work, caregiver burden was categorized by time spent caregiving and perceived stress from caregiving. For the 34% of women who provided informal care for ≥15 hours per week, 42% described caregiving as moderately to extremely stressful. Pooled multivariate analyses indicated no difference in ovarian cancer risk for women providing ≥15 hours of care per week compared to noncaregivers (hazard ratio [HR] = 0.96; 95% confidence interval [CI], 0.79-1.18), and no association was evident for women who reported moderate or extreme stress from caregiving compared to noncaregivers (HR = 0.96; 95% CI, 0.75-1.22). Together with prior work evaluating job strain and ovarian cancer risk, our findings suggest that, when evaluating a stressor's role in cancer risk, it is critical to consider how the stressor contributes to the overall experience of distress. This article is part of a Special Collection on Gynecological Cancer.