Immediate risk of suicide and cardiovascular death after a prostate cancer diagnosis: cohort study in the United States

Abstract

Background: Receiving a cancer diagnosis is a stressful event that may increase risks of suicide and cardiovascular death, especially soon after diagnosis.

Methods: We conducted a cohort study of 342,497 patients diagnosed with prostate cancer from January 1, 1979, through December 31, 2004, in the Surveillance, Epidemiology, and End Results Program. Follow-up started from the date of prostate cancer diagnosis to the end of 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 prostate cancer patients with those of the general US male population, with adjustment for age, calendar period, and state of residence. We compared risks in the first year and months after a prostate cancer diagnosis. The analyses were further stratified by calendar period at diagnosis, tumor characteristics, and other variables.

Results: During follow-up, 148 men died of suicide (mortality rate = 0.5 per 1000 person-years) and 6845 died of cardiovascular diseases (mortality rate = 21.8 per 1000 person-years). Patients with prostate cancer were at increased risk of suicide during the first year (SMR = 1.4, 95% confidence interval [CI] = 1.2 to 1.6), especially during the first 3 months (SMR = 1.9, 95% CI = 1.4 to 2.6), after diagnosis. The elevated risk was apparent in pre-prostate-specific antigen (PSA) (1979-1986) and peri-PSA (1987-1992) eras but not since PSA testing has been widespread (1993-2004). The risk of cardiovascular death was slightly elevated during the first year (SMR = 1.09, 95% CI = 1.06 to 1.12), with the highest risk in the first month (SMR = 2.05, 95% CI = 1.89 to 2.22), after diagnosis. The first-month risk was statistically significantly elevated during the entire study period, and the risk was higher for patients with metastatic tumors (SMR = 3.22, 95% CI = 2.68 to 3.84) than for those with local or regional tumors (SMR = 1.57, 95% CI = 1.42 to 1.74).

Conclusion: A diagnosis of prostate cancer may increase the immediate risks of suicide and cardiovascular death.