Risks for fatal heart attacks soon after prostate cancer diagnosis
Posted Dec 15 2009 12:00am
A new study that examined data from nearly 170,000 Swedish prostate cancer patients over more than 40 years has suggested that newly diagnosed men are at significantly increased risk for cardiovascular events such as heart attacks and also for suicide.
The Swedish nationalized health and social services system makes it possible to track health information about the entire population, so Fall et al. were able to search databases on over 4 million males in Sweden for a diagnosis of prostate cancer between January 1, 1961 and December 31, 2004. They found a total of 168,584 prostate cancer patients.
They were then able to look at the occurrence of cardiovascular events and suicides among these patients within 1 year of diagnosis and compare these data to analogous data for men with no cancer diagnosis at all.
Here is what they found:
For patients diagnosed between 1961 and 1986
During the first week after diagnosis, the relative risk of a fatal cardiovascular event was 11.2
During the first year after diagnosis, the relative risk of a fatal cardiovascular event was 1.9
For patients diagnosed between 1987 and 2004
During the first week after diagnosis, the relative risk of a fatal cardiovascular event was 2.8
During the first year after diagnosis, the relative risk of a fatal cardiovascular event was 1.3
The relative risk of suicide remained stable across the entire study period at 8.4 during the first week and 2.6 during the first year after diagnosis.
Patients who were ≤ 54 years of age at diagnosis had the highest relative risks of cardiovascular events and of suicide.
Now there are all sorts of cautions that need to be addressed in assessing the validity of the data presented in this study, and the interested reader may wish to read the Editor’s Summary that appears with the full article in the journal PLoS Medicine. However, there are a couple of things that would seem to be fairly clear:
In Sweden, prior to the introduction of the PSA test, when men could reasonably expect that any diagnosis of prostate cancer would show advanced disease, the risk of a fatal cardiovascular event within a week of a diagnosis was about 11 times higher than in men with no diagnosis of cancer.
In Sweden, after the introduction of the PSA test, this risk dropped to being only about three times as high as in men with no diagnosis.
In Sweden, there is a significant risk for suicide within a week of a prostate cancer diagnosis, and this has not been changed by the introduction of the PSA test.
It is probably reasonable to assume that the introduction of the PSA test (and the concomitant understanding that the patient has been diagnosed much earlier in the disease process) does have something to do with the reduction in risk for a fatal heart attack — but then why wouldn’t it also reduce the risk for suicide?
It is probably not reasonable to assume that these data are necessarily translatable to other countries. The data do offer an hypothesis that could probably be tested in other countries, but we would need to see a lot more data before we should conclude that — as of today — American males (for example) are three times as likely to have a fatal heart attack in the week following a diagnosis of prostate cancer than American males with no diagnosis.
We point this out because some media are already misrepresenting (sensationalizing?) this study to suggest that, “Men are up to 11 times more likely to die from cardiac problems in the week after being told they have [prostate cancer], with younger men and those with no history of heart disease at particular risk” (see the report in the UK’s Daily Mail today).