That's the finding of a study in today's online issue of Cancer.
Researchers looked at the long-term health effects of extreme stress caused by the death of child. The study included 21,062 Danish parents who suffered the death of a child and 293,745 parents who didn't experience the death of a child.
The parents were tracked for up to 18 years for the incidence of all cancers and then for specific cancers such as breast cancer, hormone-related cancers and smoking-related cancers.
The study found no associations between extreme psychological stress and cancer risk. However, it did find that mothers who lost a child had a slightly increased risk for development of smoking-related cancers compared to fathers who'd experienced the death of child and mothers who hadn't lost a child.
The researchers say that suggests any increased cancer risk may actually be linked to unhealthy, stress-induced behaviors such as smoking.
It's a popular belief that stress can cause cancer. The idea is that psychological stress reduces the immune system's ability to detect and fight cancer and increases production of hormones -- such as estrogen -- that result in tumor growth.
The study authors say their findings agree with most previous studies that suggest there is little or no link between stressful life events and increased risk of cancer.
An American Psychological Association article looks at the link between stress and cancer.