Causes of Death in Elderly Prostate Cancer Patients and in a Comparison Nonprostate Cancer Cohort

Background: Prostate cancer tends to affect older men and to progress relatively slowly. Since the prevalence of comorbidity increases with advancing age, competing causes of death are important contributors to death rates among prostate cancer patients. Accurate determination of the underlying causes of death in older men dying with prostate cancer may thus also be more difficult. Methods: We compared the distribution of underlying causes of death in decedents from a population-based cohort of elderly prostate cancer patients to that from a population-based comparison cohort of elderly men without prostate cancer. Among decedents from the prostate cancer patient cohort, we examined associations of patient demographics, disease stage, and initial treatment, with assignment of a prostate cancer underlying cause of death (versus any other cause) by use of multivariable logistic regression. In the subgroup of prostate cancer patient decedents having underlying causes of death other than prostate cancer, the underlying cause distribution was compared with that in nonprostate cancer cohort decedents. Results: Prostate cancer was the underlying cause for 39% (95% confidence interval [CI] = 36.3–41.9) of the decedents in the prostate cancer cohort. Causes of death among prostate cancer patients not dying of prostate cancer were similar to those among the nonprostate cancer cohort decedents. However, in those who were aggressively treated, the adjusted odds of other cancer causes of death were 51% higher (odds ratio [OR] = 1.51; 95% CI = 1.08–2.10) than that in nonprostate cancer patient decedents, while in those treated with watchful waiting the adjusted odds were 34% lower (OR = 0.66; 95% CI = 0.47–0.93). Conclusions: Initial treatment may influence the underlying cause of death reported in vital statistics for prostate cancer patients.