Suicide and cardiovascular mortality after a diagnosis of prostate cancer in the USA
Posted Feb 15 2010 12:00am
In December last year, we commented on a paper that reported the short-term risks for cardiovascular mortality and suicide among Swedish men diagnosed with prostate cancer between 1961 and 2004. A new study provides analogous data for American males diagnosed with prostate cancer between 1979 and 2004.
In this second paper, Fang et al. report data from a cohort of 342,497 US patients diagnosed with prostate cancer and identified through the Surveillance, Epidemiology, and End Results (SEER) program over a total of 25 years. Follow-up of each patient started on the date of prostate cancer diagnosis and ran through to the end of the first 12 calendar months after diagnosis. The relative risks of suicide and cardiovascular death were calculated as standardized mortality ratios (SMRs), comparing corresponding incidences among the prostate cancer patients with those of the general US male population.
The study results show the following:
148 men died of suicide during the 12-month follow-up period (mortality rate = 0.5/1,000 person-years).
6,845 died of cardiovascular diseases during the 12-month follow-up period (mortality rate = 21.8/1,000 person-years).
Patients with prostate cancer were at increased risk of suicide during the first year after diagnosis (SMR = 1.4), and especially during the first 3 months after diagnosis (SMR = 1.9).
The elevated risk of cardiovascular death was apparent in the pre-PSA era (1979-1986) and in the early PSA era (1987-1992) but not since PSA testing has been commonplace (1993-2004).
The overall risk of cardiovascular death was slightly elevated during the first year after diagnosis (SMR = 1.09), with the highest risk in the first month after diagnosis (SMR = 2.05).
The first-month risk for cardiovascular mortality was significantly elevated during the entire study period, and the risk was higher for patients with metastatic tumors (SMR = 3.22) than for those with local or regional tumors (SMR = 1.57).
The authors conclude that a diagnosis of prostate cancer may increase the immediate risks of suicide and cardiovascular death.
In interpreting these data it should be recognized that, prior to the PSA era, most patients were diagnosed with advanced or metastatic prostate cancer, and that the treatments used to manage these patients have all been associated with cardiovascular side effects — including mortality. It is also worth noting that the risks for both suicide and cardivascular mortality in American patients appear to be notably lower than the same risks in the Swedish patients studied by Fall et al. No explanation for this is offered in the abstracts of the two papers, although there may be discussion of possible reasons in the full text of the current paper.