Death From Heart-Related Causes May Affect Cancer Survivors More Than the General Population

March 8, 2021
Darlene Dobkowski, MA

More than half of the deaths assessed in this study were related to non-cancer-related causes such as cardiovascular disease compared with cancer-related causes, which may reflect a need for risk factor management for heart disease during survivorship.

Patients who were alive five years after receiving a cancer diagnosis were more likely to die from cardiovascular disease compared with the general population, according to study results published in the Medical Journal of Australia.

In particular, some of the leading causes of death included ischemic heart disease (or damage in the heart’s blood vessels) and cerebrovascular disease (or stroke), according to the study results.

“Cancer control systems should incorporate monitoring of long-term survivorship outcomes including non-cancer-related mortality and managing risk factors for premature death from non-cancer causes,” the study authors wrote.

In this study, researchers analyzed data from 32,646 patients (50% men; mean age at diagnosis, 60 years) from South Australia who were alive five years after receiving their initial diagnosis of cancer. The most common cancer types among these patients included prostate (18.3%), breast (19.2%), gastrointestinal (15.4%) and skin (15.9%). In addition, 4.8% of patients had multiple cancer types.

The goal of the study was to assess cancer-specific mortality and all-cause mortality by cancer type. Patients were followed up until 2016 for a median of 17 years.

During follow-up, 53% of patients died at a mean age of 81 years. Of these deaths, 45% were associated with cancer and 55% were related to non-cancer-related causes. The most common cause of death was ischemic heart disease (15.7%). Other common causes of death included prostate cancer (9.3%), cerebrovascular disease (7.7%) and breast cancer (7.3%).

Researchers also calculated the overall standardized mortality ratio, defined as a ratio of deaths of patients in this study compared with an estimated number of deaths in the general population. The overall standardized mortality ratio was 1.24 after the researchers took into consideration factors such as sex, age and the year of cancer diagnosis.

Study results demonstrated that the number of deaths from cardiovascular disease exceeded that of deaths from cancer-related causes approximately 13 years after patients received their diagnosis of cancer.

“Our findings may partly reflect the high prevalence of and mortality from cardiovascular disease in Australia, but we also found that cardiovascular mortality was higher than in the general population,” the study authors wrote. “Our findings suggest an interaction between cancer or its treatment and cardiovascular risk factors. The interaction may reflect a biological phenomenon (such as the direct toxic effect of anti-cancer treatment on the heart or vascular system), or it may reflect lack of prioritization of cardiovascular disease by patients, or health care focused on treating cancer.”

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