Background: To date, adverse events of prostate cancer (PCa) treatment have only been studied as a single event, and little is known about the risk of subsequent adverse events.
Objective: We assessed the frequency of multiple events (fractures, stroke, heart disease [HD], and thromboembolic disease [TED]) following PCa diagnosis.
Design, setting, and participants: PCBaSe Sweden is based on the National Prostate Cancer Register (NPCR) that covers >96% of incident PCa cases in Sweden.
Measurements: We evaluated the number of events (fractures, stroke, HD, and TED) leading to hospitalisation recorded in the National Hospital Discharge Registry after PCa diagnosis and conducted multivariate age-adjusted Cox proportional hazards regression to estimate the risk of developing multiple events.
Results and limitations: Between 1997 and 2007, 30 642 men received primary endocrine treatment, 26 432 curative treatment, and 19 526 surveillance: 75% had no event during follow-up, 17% had one event, and 9% had more than one event. The incidence of any event was 102 in 1000 person-years. Men who already had experienced an event, particularly HD, before or after the date of PCa diagnosis were more likely to have multiple events afterwards. For example, the hazard ratio of developing a third event for those with two or more events of HD before PCa diagnosis was 1.40 (95% confidence interval, 1.28-1.52) compared with those with no events of HD before PCa diagnosis. Events treated without hospitalisation were not included, so the number of adverse events is possibly underestimated.
Conclusions: A third of PCa patients with an adverse event after treatment subsequently experienced another adverse event, but apart from history of HD or stroke before PCa diagnosis, no specific characteristics were found for these men. Thus PCa management needs to take into account the risk of adverse events in all PCa patients, especially those with a history of adverse events before PCa diagnosis.
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