Cardiovascular Disease Mortality Patterns Among People With Cancer in New South Wales, Australia: A Population‐Wide Data Linkage Study

TL;DR

This study finds that people with cancer in Australia have higher cardiovascular disease mortality rates compared to the general population, especially in the early years after diagnosis.

Contribution

The study provides population-wide insights into cardiovascular disease mortality patterns among cancer patients in New South Wales over a 35-year period.

Findings

CVD mortality rates were higher than expected in the first two years after cancer diagnosis.

Lung cancer and distant metastases were associated with the highest CVD mortality risk.

CVD mortality rates declined over time, especially in recent years.

Abstract

To investigate cardiovascular disease (CVD) mortality patterns among people with cancer in New South Wales (NSW) compared to the NSW general population and trends over time.

Population‐wide retrospective data‐linkage study.

873,344 people aged ≥ 40 diagnosed with primary invasive cancer and registered in the NSW Cancer Registry between 1985 and 2019.

CVD as the underlying cause of death. Absolute mortality rate (AMR, per 10,000 person‐years) and standardised mortality ratios (SMR) compared to the NSW general population.

Of 514,865 people with cancer who died between 1985 and 2020, 71% (n = 303,770) died from cancer and while 14% (n = 73,733) from CVD. AMR of CVD increased with time since cancer diagnosis (≤ 2 years: AMR = 124 vs. > 10 years: AMR = 152) and declined from 188 in 1985–1995 to 68 in 2010–2020 following cancer diagnosis in 1985–1989 and 2010–2014, respectively. Approximately 45% of CVD deaths were due to ischaemic heart disease, with 49% in males versus 40% in females. Elevated SMRs of CVD were found for ≤ 2 years after cancer diagnosis (SMR = 1.17, 95% CI: 1.15, 1.19), those aged 40–59 (SMR = 1.13, 95% CI: 1.07, 1.19) and those diagnosed with distant metastases (SMR = 1.31, 95% CI: 1.27, 1.35) or lung cancer (SMR = 1.42, 95% CI: 1.37, 1.47). Lower CVD SMRs were observed for > 2 years after cancer diagnosis (e.g., for 2–5 years: SMR = 0.84, 95% CI: 0.83, 0.86), among people diagnosed with cancers with higher survival rates (e.g., Melanoma: SMR = 0.79, 95% CI: 0.78, 0.81) and in the most recent period 2010–2020 (SMR = 0.85, 95% CI: 0.83, 0.87).

Higher than expected CVD mortality compared to the general population was observed within the first few years after cancer diagnosis, especially among those diagnosed with lung cancer and distant metastases, which might reflect shared risk factors and cardiotoxic treatment. Our findings underscore the need for CVD risk assessment, prevention, and care among people with cancer.

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