The shock of a cancer diagnosis can have deadly consequences, according to a new study that linked the diagnosis to an increased risk of suicide, heart attack and stroke.
The Swedish study followed more than 6 million adult men and women, 786 of whom were diagnosed with various cancers during the 15-year follow-up. Compared to their cancer-free counterparts, people who were recently diagnosed with cancer had a 12.6 percent higher risk of suicide and a 5.6 percent higher risk of cardiovascular death from heart attack, stroke or heart failure.
"Our findings suggest that a cancer diagnosis constitutes a major stressor, one that immediately affects the risk of critical, fatal outcomes," the researchers wrote in their report published today in the New England Journal of Medicine.
The risk of suicide and cardiovascular death was highest the week following a cancer diagnosis and decreased over time.
"What we're really looking at is the psychological stress associated with receiving the news," said study co-author Dr. Murray Mittleman, director of cardiovascular epidemiology at Beth Israel Deaconess Medical Center in Boston. "It can be a very big shock."
More than 1.6 million people will be diagnosed with cancer in 2012, according to the American Cancer Society.
"I think a lot of people would be surprised to know that the news of a cancer diagnosis would have such a profound effect," said Holly Prigerson, director of psychosocial oncology at the Dana-Farber Cancer Institute in Boston. "We should recognize that it's alarming, it's shocking, and there needs to be a way to protect vulnerable people who are psychologically fragile and less able to withstand the emotional blow of the bad news."
Prigerson said the news can trigger post-traumatic stress disorder and depression, both of which increase the risk of suicide. It can also cause a rise in heart rate and blood pressure, which boosts the risk of heart attack and stroke.
The risk of death from either suicide or cardiovascular disease was highest for patients with poor prognoses associated with brain tumors and cancers of the esophagus, liver, pancreas and lung.
"Patients might be thinking, 'I'm going to die a grizzly death, so I'm going to kill myself now rather than wait for this to unfold," said Prigerson.
The risk was lowest for patients diagnosed with skin cancer.
Prigerson's own research suggests more than half of patients are traumatized by their cancer diagnoses.
"Fifty-seven percent of our sample said they were made terrified or horrified by the news," she said. "It speaks to the psychological devastation wrought by a cancer diagnosis and the need for clinicians to be acutely aware of and sensitive to the impact of this news."
The suicide rate in Sweden is 12.7 per 100,000, according to the World Health Organization, which is slightly higher than the 12 per 100,000 reported in the U.S. But Prigerson said the study's findings can be generalized to American patients.
"These findings are consistent with research on the psychological trauma of a cancer diagnosis here in the U.S.," said Prigerson, adding that Swedish registries allow detailed epidemiological research. "It demonstrates, I think, fairly unequivocally, the impact of psychological stress on physical health."
All the cancer diagnoses reported in the study were confirmed. But Mittleman said the results also have implications for cancer screening programs, which have been criticized for generating false positives that lead to risky tests and procedures as well as anxiety.
"It points to the fact there may be unintended adverse effects of programs we think are strictly beneficial," he said.