Death of a Child and Mortality after Cancer: A Nationwide Cohort Study in Sweden

Background: The death of a child is a traumatic life event that may influence mortality in patients with cancer. Only a few studies investigated this association and their findings have been mixed. We analyzed whether the death of a child is associated with mortality in patients with cancer. Methods: We conducted a cohort study of 371,673 parents who were diagnosed with cancer in Sweden during 1973 to 2014 by linking several population-based registers. We analyzed the association between the death of a child after the diagnosis of cancer and mortality using Cox proportional hazards models with time-varying exposure. Results: The death of a child was associated with an increased risk of mortality HR, 1.27; 95% confidence intervals (CI) 1.17-1.39). The association was present not only in case of children's death due to cancer or other natural deaths, but also in case of unnatural deaths. Mortality was increased only in the long-term follow-up period (HR, 1.42; 95% CI, 1.29-1.56), but not in the short-term (HR, 0.95; 95% CI, 0.78-1.15). The association was most pronounced following loss of an adult child and for patients with reproductive cancers. Conclusions: Death of a child is associated with increased risks of overall and long-term mortality in patients with cancer. The findings that the association was present not only in case of natural but also in case of unnatural deaths suggests that stress-related mechanisms may also operate. Impact: Our findings highlight the importance of psychosocial support for patients with cancer experiencing severe stress.