Factors Associated With Major Adverse Cardiovascular Events in Survivors of Colorectal Cancer
Colorectal cancer survivors’ risk for heart attack—five times that of the average person—may be linked to the amount of fat stored within the abdomen and abdominal muscles, not to body mass index (BMI), according to a new study of 2,800 colon cancer survivor health outcomes published by Brown et al in JAMA Oncology.
Methodology
Current clinical practice guidelines for colorectal cancer survivors now recommend using BMI to guide heart disease risk management. “At the time the guidelines were developed, little data had been gathered on the best way to manage colorectal cancer survivors’ heart disease risk,” said Justin Brown, PhD, primary investigator of the study and Director of the Cancer Metabolism Program at Louisiana State University’s Pennington Biomedical Research Center.
Researchers reviewed long-term cardiovascular outcomes of 2,839 colorectal cancer survivors in Kaiser Permanente’s Northern California region. Patients with colon cancer typically undergo a computed tomography (CT) scan before surgery to determine if the cancer has spread to the chest, abdomen, or pelvis; these results were used to assess body fat and the subsequent risk of cardiovascular disease.
Study Results
The cumulative incidence of a major adverse cardiovascular event 10 years after the diagnosis of colorectal cancer was 19.1%. BMI was positively correlated with some CT-derived measures of body composition, but BMI was not associated with major adverse cardiovascular events; contrasting BMI categories of greater than or equal to 35 vs 18.5 to 24.9, the hazard ratio was 1.23 (95% confidence interval = 0.85–1.77; P = .50 for trend). Visceral adipose tissue area and muscle radiodensity were associated with major adverse cardiovascular events; subcutaneous adipose tissue area and muscle mass were not associated with major adverse cardiovascular events.
“This study demonstrates the importance at every BMI level of having more precise measures of muscle and fat to help identify those patients who are at high risk of developing cardiovascular disease,” said study coauthor Bette J. Caan, DrPH, research scientist in the Kaiser Permanente Division of Research.
“If a patient has a high amount of fat in their abdomen, his or her physician might recommend some combination of diet, exercise, and medication to reduce the risk of heart attack,” said Dr. Brown. “The study shows physicians already have the tools and information needed to identify the patients at the highest risk for heart attacks.”
“Contrary to popular belief, a person may have a normal body weight (and BMI) but have a lot of fat in their bodies; therefore, it can be a hidden condition, hence the need for a more sophisticated measurement, like we did in this study,” concluded study coauthor Carla Prado, PhD, Associate Professor at the University of Alberta.
Disclosure: The research was supported by the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
