For any parent, losing a child is devastating. But for parents who have also been diagnosed with cancer, a child’s death may mean a lower likelihood of long-term survival. So found Swedish researchers in a review of population-based registry data collected between 1973 and 2014.

In the journal Cancer Epidemiology, Biomarkers & Prevention, the researchers hypothesized that bereavement may incite behavioral, hormonal and immunological changes that increase mortality risk, according to Cancer Therapy Advisor. “Our findings highlight the importance of psychosocial support for patients with cancer experiencing severe stress,” they wrote.

Led by Yujie Wang, a global public health researcher at the Karolinska Institutet in Stockholm, the researchers analyzed data on 371,673 Swedish parents diagnosed with cancer during the study time period.

They found that the 4,099 parents who had also experienced the death of at least one child after their diagnosis were at higher risk of long-term mortality. That was especially true if the child was above age 18 or an only child or if the parent had a cancer of the reproductive organs. The loss of a child did not appear to increase risk for short-term mortality—five years or less—but did increase risk for long-term mortality.

The manner of death did not seem to influence risk. Parents of children who had died of so-called natural causes such as a disease or disorder fared no better than parents of children who had died due to an accident or act of violence.

The results of the study suggest that the loss of a child is a risk factor for cancer-related mortality and mortality in general.

To read more about how mental health can affect cancer outcomes, click here. To read about resources for kids whose parents have cancer, click here. And to learn how to reduce stress, click here.