Cardiovascular and other competing causes of death among patients with cancer from 2006 to 2015: An Australian population-based study

Abstract

Background: With improved cancer survivorship, cardiovascular disease (CVD) and other noncancer events compete with cancer as the underlying cause of death, but the risks of mortality in competing-risk settings have not been well characterized.

Methods: The authors identified 21,637 individuals who had a first cancer registered between 2006 and 2013, with follow-up to 2015, in the Australian population-based Tasmanian Cancer Registry. The cumulative incidence of deaths from specific competing events was assessed in competing-risk analyses. Standardized mortality ratios (SMRs) and absolute excess risks (AERs) for deaths from noncancer causes were calculated for comparison with the general population.

Results: Overall, 8844 deaths were observed, with 1946 (22%) from competing events. The cumulative incidence of deaths from CVD increased significantly with age at first cancer diagnosis and exceeded other competing events at age ≥65 years. The risk of death from CVD was more common than expected in the first year of follow-up (SMR, 1.44 [95% confidence interval, 1.26-1.64]; AER, 36.8 per 10,000 person-years). The SMR and AER for CVD deaths varied by first cancer site, indicating increased risks after a first diagnosis of lung cancer, hematologic malignancy, and urinary tract cancer. For other noncancer events, the SMRs increased significantly for deaths from infectious disease and respiratory disease and were highest in the first year of follow-up.

Conclusions: CVD was the leading cause of competing mortality among Tasmanian patients with cancer who were diagnosed from 2006 to 2013. The higher than expected occurrence of death from CVD and other noncancer events during the first year after a cancer diagnosis highlights the importance of early preventive interventions.

Keywords: cancer; cardiovascular mortality; competing risk; noncancer mortality; population-based.