In a study reported in The Lancet, Strongman et al found that survivors of most site-specific cancers had an increased risk for one or more cardiovascular diseases during follow-up compared with a matched control group of patients without cancer.
This population-based cohort study employed multiple linked electronic health records databases in the United Kingdom to identify cohorts of survivors of the 20 most common cancers who were alive 12 months after diagnosis, and controls with no history of cancer matched for age, sex, and general practice. In total, the analysis included 126,120 patients with cancer (diagnosed between January 1990 and December 2015 still being followed up at least 1 year after diagnosis) and 523,541 matched controls.
The risk of venous thromboembolism was increased in survivors of 18 of 20 site-specific cancers, with adjusted hazard ratios ranging from 1.72 (95% confidence interval [CI] = 1.57–1.89) after prostate cancer to 9.72 (95% CI = 5.50–17.18) after pancreatic cancer. Although hazard ratios decreased over time, risk remained elevated more than 5 years after diagnosis.
The risk of heart failure or cardiomyopathy was increased in 10 of the 20 cancers analyzed; among these, adjusted hazard ratios were 1.94 (95% CI = 1.66–2.25) for non-Hodgkin lymphoma, 1.77 (95% CI = 1.50–2.09) for leukemia, 3.29 (95% CI = 2.59–4.18) for multiple myeloma, 1.96 (95% CI = 1.46–2.64) for esophageal cancer, 1.82 (95% CI = 1.52–2.17) for lung cancer, 1.73 (95% CI = 1.38–2.17) for kidney cancer, and 1.59 (95% CI = 1.19–2.12) for ovarian cancer.
The risks of arrhythmia, pericarditis, coronary artery disease, stroke, and valvular heart disease were increased for multiple cancer sites. Survivors of hematologic malignancies had increased risks for all these cardiovascular outcomes, and the pattern of risks varied for other cancer sites.
Increased relative risks for heart failure or cardiomyopathy and venous thromboembolism were most pronounced in younger cancer survivors and in those with no previous cardiovascular disease or hypertension. However, absolute excess risks were generally higher with increasing age.
Although the causes of increased cardiovascular disease risks in the patient groups are likely to be varied, the analyses suggest that cancer treatment, particularly chemotherapy, had a more pronounced effect on risk than such shared risk factors as smoking and excess weight.
The investigators concluded, “Survivors of most site-specific cancers had increased medium-term to long-term risk for one or more cardiovascular diseases compared with that for the general population, with substantial variations between cancer sites.”
Krishnan Bhaskaran, PhD, of the Department of Noncommunicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, is the corresponding author for The Lancet article.
Disclosure: The study was funded by the Wellcome Trust and Royal Society. For full disclosures of the study authors, visit thelancet.com.