In an English retrospective cohort study reported in JACC: CardioOncology, Strongman et al found that cardiovascular mortality in older cancer survivors ultimately exceeded mortality from common primary cancers in the time since their primary cancer diagnosis. However, the eventual predominance of cardiovascular mortality was less frequent when compared with total cancer mortality.

As stated by the investigators, “Cancer survivors have a higher risk for developing cardiovascular diseases than the general population. The aim of this study was to investigate whether cardiovascular mortality overtakes cancer-specific mortality during cancer survivorship and, if so, at what point cardiovascular disease becomes the dominant cause of death.”

Study Details

The study used data from linked English electronic health records on 104,028 adults aged ≥ 40 years with a first cancer diagnosis of nine common primary cancers who were alive at least 1 year after diagnosis. The nine primary cancers consisted of colorectal, lung, breast, uterine, prostate, and bladder cancers, as well as malignant melanoma, non-Hodgkin lymphoma, and leukemia.

Cardiovascular and Cancer Deaths

Among the 104,028 survivors, over a median follow-up from 1 year after cancer diagnosis of 4.8 years (interquartile range = 2.0–8.7 years), death due to cardiovascular causes occurred in 7,091 patients; death due to any of the nine primary cancers occurred in 19,758 patients; and death due to any of the cancers occurred in 25,666 patients. Mortality from the primary cancer at ≥ 1 year after diagnosis was highest for lung and colorectal cancers; moderate for malignant melanoma, uterine cancer, bladder cancer, non-Hodgkin lymphoma, and leukemia; and lowest for breast and prostate cancers.

Cardiovascular Mortality and Mortality From Primary Cancer

In analysis including the 19,758 patients who died from primary cancer, cardiovascular mortality overtook mortality due to primary cancer for all nine cancers among survivors aged ≥ 80 years at diagnosis at time points ranging from 1.9 to 10.6 years after diagnosis, and for all cancers except leukemia and prostate cancer in those aged 60 to 79 years at diagnosis at time points ranging from 4.8 to 17.4 years after diagnosis. The earliest crossover points for both these age groups were for malignant melanoma (1.9 and 8.5 years, respectively), bladder cancer (2.6 and 4.8 years), and uterine cancer (3.9 and 7.1 years). Among patients aged 40 to 59 years at diagnosis, cardiovascular mortality remained low over time and overtook primary cancer mortality only for uterine cancer (after 11.0 years).

Analysis by Total Cancer Mortality

In analysis including the 25,666 patients who died from any of the nine cancers (including those who died from primary cancer), cardiovascular mortality overtook total cancer mortality for six cancers (colorectal, lung, breast, uterine, bladder, and malignant melanoma) among survivors aged ≥ 80 years at diagnosis at time points ranging from 5.9 years (uterine) to 17.1 years (lung) after diagnosis, and for two cancers (uterine and malignant melanoma) among those aged 60 to 79 years at diagnosis at time points of 17.5 years (uterine) and 19.6 years (malignant melanoma) after diagnosis. Among patients aged 40 to 59 years at diagnosis, cardiovascular mortality did not overtake total cancer mortality for any of the cancers during follow-up.

The investigators concluded, “In older survivors of nine common cancers, cardiovascular mortality becomes dominant over mortality from the primary cancer, though not always over total cancer mortality, as time passes since cancer diagnosis.”

Krishnan Bhaskaran, PhD, of the London School of Hygiene and Tropical Medicine, Department of Non-Communicable Disease Epidemiology, is the corresponding author for the JACC: CardioOncology article.

Disclosure: The study was supported by the Wellcome Trust and the Royal Society. For full disclosures of the study authors, visit jacc.org.