Being diagnosed with prostate cancer roughly doubles the risk of suicide or death from a heart attack, U.S. researchers said on Tuesday, adding to the harm linked with diagnosis of this often slow-growing cancer.
A team at Harvard and Brigham & Women's Hospital in Boston used data from more than 340,000 prostate cancer patients diagnosed between 1979 and 2004, comparing rates of suicide and deaths from heart disease to those in the general population.
"We were interested in that window of time in the year following diagnosis," said Lorelei Mucci of Brigham & Women's and the Harvard School of Public Health, who worked on the study published in the Journal of the National Cancer Institute.
In that period, the team saw a 90 percent increase in the risk of suicide among men diagnosed with prostate cancer compared with men in the general population.
Overall, 148 men committed suicide. Mucci said while the number is small, the suicide rate is still far higher than the expected rate based on rates of suicide among men in the general population in a year.
The increased risk of death was even greater for heart attacks and strokes. "There, it was a doubling of risk," Mucci said in a telephone interview.
She said the risk of having a heart attack appears to be greater than having a stroke, corresponding with a number of studies that have found the stress from a sudden calamity, such as an earthquake, can raise heart attack rates.
The elevated suicide risk was most strongly tied to the period before screening for prostate cancer using the prostate-specific antigen or (PSA) blood test became standard practice in 1993.
"We still see an increased risk for cardiovascular death, which is about 60 percent greater in that first month after diagnosis, but we don't see an increased risk for suicide, which is a positive thing," Mucci said.
She said that may suggest that men are getting counseling when they get their test results.
However, a large study in Sweden last month by the same team did find an elevated suicide risk associated with PSA testing, Mucci said.
Prostate cancer is the second most common cancer worldwide after lung cancer, killing 254,000 men a year globally.
Doctors have routinely recommended PSA screening in men over 50 based on the assumption that early diagnosis and treatment is better than standing by and doing nothing.
Screening can catch serious cancers, but a study last year found routine prostate cancer screening resulted in more than 1 million U.S. men being diagnosed and treated for tumors growing too slowly to do any harm.
Standard forms of treatment — surgery, radiation or hormone therapy — all can cause harm, resulting in impotence and incontinence in about a third of patients.
"Our study brings one more piece of the puzzle, which is the stress associated with the diagnosis itself," Mucci said.
She said the findings suggest more men need counseling and support after a prostate cancer diagnosis.
"That is where we hope our finding can add to clinical practice," she said.