In an English retrospective cohort study reported in JACC: Cardio-Oncology, Helen Strongman, PhD, of the Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, and colleagues found that cardiovascular mortality ultimately exceeded mortality from common primary cancers in older cancer survivors over time from primary cancer diagnosis, although eventual dominance of cardiovascular mortality was less frequent when compared with total cancer mortality.¹

Helen Strongman, PhD

Krishnan Bhaskaran, PhD

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.”

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

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 between January 1990 and December 2015 who were alive at ≥ 1 year after diagnosis. The nine primary cancers consisted of colorectal cancer, lung cancer, malignant melanoma, breast cancer, uterine cancer, prostate cancer, bladder cancer, non-Hodgkin lymphoma, and leukemia. Among all patients, age at diagnosis was 67.7 ± 11.9 years.

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 these cancers (including those who died from primary cancer) occurred in 25,666 patients; 71,271 survivors remained alive at the conclusion of the study period at the end of December 2015. 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 an 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 from cancer diagnosis of 1.9 years for malignant melanoma, 2.6 years for bladder cancer, 3.9 years for uterine cancer, 4.7 years for non-Hodgkin lymphoma, 5.4 years for colorectal cancer, 6.3 years for leukemia, 7.1 years for breast cancer, 8.9 years for prostate cancer, and 10.6 years for lung cancer.

Among patients aged 60 to 79 years at diagnosis, cardiovascular mortality overtook mortality due to primary cancer for all cancers except leukemia and prostate cancer. Time points for crossover after cancer diagnosis were 4.8 years for bladder cancer, 7.1 years for uterine cancer, 8.5 years for malignant melanoma, 8.6 years for colorectal cancer, 12.7 years for breast cancer, 15.4 years for non-Hodgkin lymphoma, and 17.4 years for lung cancer.

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 years.

Analysis by Total Cancer Mortality

In an 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 among patients aged ≥ 80 years at diagnosis, excluding prostate cancer, non-Hodgkin lymphoma, and leukemia. Crossover occurred at 5.9 years for uterine cancer, 8.3 years for colorectal cancer, 8.8 years for malignant melanoma, 9.3 years for bladder cancer, 10.4 years for breast cancer, and 17.1 years for lung cancer.

Among those aged 60 to 79 years at diagnosis, cardiovascular mortality overtook total cancer mortality for two cancers, consisting of uterine cancer, with crossover at 17.5 years, and malignant melanoma, with crossover at 19.6 years. 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.” 

DISCLOSURE: The study was supported by the Wellcome Trust and the Royal Society. Dr. Strongman reported no conflicts of interest. Dr. Bhaskaran has received research support from the Wellcome Trust, Royal Society, Medical Research Council, British Heart Foundation, and Diabetes UK.

REFERENCE

1. Strongman H, Gadd S, Matthews AA, et al: Does cardiovascular mortality overtake cancer mortality during cancer survivorship? An English retrospective cohort study. JACC: CardioOnc 4:113-123, 2022.