Childhood cancer survivors are 80% more likely to be undertreated for cardiovascular risk factors

Adults who survive childhood cancer have a higher risk of cardiovascular disease than the general population, but they are 80% more likely to be undertreated for several cardiovascular risk factors: hypertension (also called high blood pressure) , diabetes and high cholesterol, according to new research published today in the Journal of the American Heart Associationan open-access, peer-reviewed journal of the American Heart Association.

Previous research has shown that due to their exposure to chemotherapy and/or radiation therapy, childhood cancer survivors may face an up to five times higher risk of cardiovascular disease and death, per compared to the general population. Several studies have shown that most adult childhood cancer survivors report receiving only general medical care, not specific to their cancer experience. Previous research also suggests that cancer survivors are not receiving recommended cardiovascular screenings in a timely manner due to limited knowledge of future health complications by survivors and healthcare professionals.

These findings make underdiagnosis and undertreatment significant concerns for the estimated half million childhood cancer survivors living in the United States. »

Eric J. Chow, MD, MPH, lead study author, associate professor of clinical research and public health sciences, Fred Hutchinson Cancer Center in Seattle

In this study, undertreatment of cardiovascular risk factors was defined as a diagnosis of high blood pressure, high cholesterol, or diabetes while having low levels of blood pressure, “bad” cholesterol, triglycerides, or blood sugar. higher than the recommendations. (No details available on diagnosis of type 1 or type 2 diabetes.)

Participants were recruited from the Childhood Cancer Survivor Study (CCSS), a large study that includes people who were diagnosed with cancer before the age of 21 between 1970 and 1999 at residential care centers. health in the United States and Canada, and who survived at least five years. Between September 2017 and April 2020, researchers recruited from the US-based group of CCSS participants childhood cancer survivors aged at least 18 years, without heart disease or heart failure, living within 80 km of nine major US metropolitan areas (Atlanta, Boston, Denver, Houston, Minneapolis, Philadelphia, Pittsburgh, Seattle and Columbus, Ohio). Those recruited were also participating in a separate clinical trial testing the potential of a telehealth plan to improve cardiovascular outcomes in long-term survivors of childhood cancer. Among this group, made up of 85% white adults and 57% women, the most common types of cancer were leukemia, lymphoma and bone cancer.

Researchers measured blood pressure, lipids, glucose and hemoglobin A1c levels in nearly 600 adults (median age 37) an average of 28 years after cancer diagnosis and obtained similar data on a group comparison of nearly 350 adults of the same age with no history of cancer. The analysis found:

• Cancer survivors were more likely than those without a history of cancer to have hypertension (18% versus 11%, respectively), abnormal lipid levels (14% versus 4.9%, respectively), and diabetes (6. 5% versus 3.2%, respectively). ).
• Participants in both groups had similar rates of underdiagnosed hypertension, hypercholesterolemia and diabetes: 27.1% in cancer survivors and 26.1% in the comparison group. However, cancer survivors were 80% more likely to be undertreated for these conditions compared to their counterparts in the study.

“Serious heart disease is rare among young adults in the general population, which includes childhood cancer survivors, therefore, greater awareness of the risk of significantly higher cardiovascular disease in those with a history of cancer is important,” Chow said. “Educating primary care professionals and improving the ability of survivors to self-manage their health can mitigate increased risks. There are specialized heart disease risk calculators designed for cancer survivors, and these may be more accurate in predicting future risk of cardiovascular disease. than risk calculators designed for the general population.”

The analysis also included results from a self-reported questionnaire assessing medical history, such as cardiovascular health and treatment; diet, exercise and other lifestyle habits; and people’s belief in their ability to manage their own health.

Information on the peer comparison group who had no history of childhood cancer came from the 2015-2016 National Health and Nutrition Survey, in which participants had standardized health exams and home interviews , comparable to the questionnaire completed by cancer survivors.

Other findings include:

• The most underdiagnosed and undertreated cardiovascular disease risk factors in cancer survivors were hypertension at 18.9% and lipid disorders at 16.3%.
• Among cancer survivors, men were twice as likely to be underdiagnosed and undertreated for cardiovascular disease risk factors; while overweight or obese survivors were 2-3 times more likely to be underdiagnosed and undertreated.
• Cancer survivors who had at least two unhealthy lifestyle factors, such as physical inactivity and low fruit and vegetable intake, were twice as likely to be undertreated than the comparison group.

The study also found that childhood cancer survivors who reported having better self-efficiency – a stronger belief in their ability to manage their own health – were 50% less likely to under-treat the cardiovascular disease risk factors studied. “This may not be surprising, but it suggests that efforts to help survivors learn to take greater ownership of their condition can help improve longer-term outcomes,” Chow said. “This has also been shown in patients with other chronic health conditions besides cancer.”

Among the limitations of the study are the potential for measurement error and misclassification among cancer survivors and the comparison group due to one-time health assessments.