Two pieces of research by the same study group, one conducted in 340,000 men in the US and the other in 170,000 men from Sweden, have found that the risk of dying from a heart attack is raised by 2 to 11 times in men with a diagnosis of prostate cancer.
In addition, the risk of suicide in the first year after diagnosis in American men with prostate cancer was 40% higher than the national average and the risk in the first three months 90% higher. Astoundingly, Swedish guys were twice as likely to kill themselves in the first three months after diagnosis than men who were cancer free.
Interestingly, the US study found that the risk of suicide was only raised between 1979 and 1992, before the widespread use of screening to detect prostate cancer early. There was no link between prostate cancer and suicide once screening, known as prostate-specific antigen (PSA) testing, was being used across the board.
So does this mean that screening for prostate cancer reduces the risk of suicide after a diagnosis? The authors think so, suggesting that early screening detects less aggressive tumors that are still treatable, thus less stress inducing.
On the other hand, the use of PSA testing has long been controversial. Many men will have small prostate tumours that never do them any harm and the test itself isn’t very reliable, so screening is associated with overdiagnosis and overtreatment.
By extension, some studies reckon that routine testing for prostate cancer causes undue stress and anxiety among patients who do not understand the implications of an abnormal result. In fact, the Swedish study did not find any difference in suicide risk between the pre-screening era and after screening had been introduced.
The authors aren’t sure about this difference between their two studies, admitting “The reason for this discrepancy is unclear.” However, it could potentially be caused by the large number of nonaggressive prostate cancers diagnosed during the later years in the US study or improved access to emotional support after diagnosis come the late 80s, which might have lessened despair among patients and reduced their suicide risk.
“These results add to the complex debate of pros and cons of extensive prostate-specific antigen testing and the many nonlethal prostate cancers thus detected,” say the authors.
Fall K et al. (2009) Immediate Risk for Cardiovascular Events and Suicide Following a Prostate Cancer Diagnosis: Prospective Cohort Study PLoS Medicine 6 (12). DOI: 10.1371/journal.pmed.1000197
Fang F et al. (2010). Immediate Risk of Suicide and Cardiovascular Death After a Prostate Cancer Diagnosis: Cohort Study in the United States JNCI Journal of the National Cancer Institute DOI: 10.1093/jnci/djp537