Age at cancer diagnosis may affect risk of death from heart disease

AHA: The age at which people are diagnosed with cancer may help determine their risk of death from heart disease, according to a new study. Heart disease has been known to be the leading cause of treatment-related, non-tumor deaths among survivors of childhood cancer, breast cancer and Hodgkin lymphoma. But the risk of cardiac mortality hasn’t been investigated comprehensively within a large population of teenage and young adult cancer survivors.

The United Kingdom-based study consisted of more than 200,000 people with cancer at ages 15-39 who survived at least five years after being diagnosed. Researchers found:

• Six percent of deaths were caused by heart disease.
• Cancer survivors diagnosed at ages 15-19 had 4.2 times higher risk of death from heart disease compared to the general population of the same age and gender.
• Survivors who were 35-39 years old at cancer diagnosis had 1.2 times higher risk of death from heart disease compared to the general population of the same age and gender.

“It is important for clinicians because it helps them focus the most intensive follow-up care on those most at risk,” said Mike Hawkins, D.Phil., study senior author and epidemiology professor and director of the Centre for Childhood Cancer Survivor Studies at the University of Birmingham in England. “It is important for survivors because it empowers them by providing them with their long-term chances of a specific side effect of cancer treatment.”
The significance of age at diagnosis was most apparent for survivors of Hodgkin lymphoma (cancer of the lymphatic system):

• Almost 7 (6.9) percent of those diagnosed at ages 15-19 had died of heart disease by age 55 compared to 2 percent of those diagnosed at ages 35-39.
• Survivors of Hodgkin lymphoma experienced 3.8 times the risk of death from heart disease than expected from the general population of the same age and gender.
• Among survivors of Hodgkin’s lymphoma 60 and older, almost 28 percent of excess deaths were due to heart disease.

Survivors of other types of cancer also had a higher than expected risk of death from heart disease including: leukemia, genitourinary cancer, lung cancer and breast cancer.
The new research provides insight into the cardiotoxicity of cancer treatments for teenagers and young adults — a growing topic of focus in medical circles. However, the study lacks detailed information on exposure to cancer treatments such as radiotherapy and chemotherapy.
“Survivors of cancer diagnosed in teenage and young adulthood are internationally acknowledged to be an under studied population,” Hawkins said. “With the advantage of long-standing cancer registration for the U.K. population, we were in a position to undertake the largest study to date, which has the advantage of being population-based and benefits from lengthy follow-up after diagnosis.”
The study is published in the American Heart Association journal Circulation.