Survivors of adolescent and young adult cancers have more than twice as high a risk of developing cardiovascular disease than people without a cancer history, according to a large cohort study.
Survivors of adolescent and young adult (AYA) cancers have more than twice as high a risk of developing cardiovascular disease (CVD) than people without a cancer history, according to a large cohort study. Leukemia and breast cancer conferred the highest risk for CVD later in life.
“Although considerable effort has been made to characterize long-term CVD outcomes in survivors of childhood cancer, few studies have adequately addressed CVD risk among survivors of cancers diagnosed after childhood,” wrote study authors led by Chun Chao, PhD, of Kaiser Permanente Southern California in Pasadena. “It has been recognized that the data from childhood cancer survivors may not be readily extrapolated to survivors of AYA cancer because the magnitude of late effects of cancer and its treatment may vary by age.”
Researchers evaluated long-term CVD outcomes, up to 12 years from diagnosis, in a Kaiser Permanente cohort of 5,673 2-year survivors of AYA cancer (diagnosed between the ages of 15 and 39 years). They compared these with 57,617 individuals without cancer, representing a total of 24,839 person-years of follow-up from the cancer survivors and 239,073 person-years among the comparison cohort. The results were published online ahead of print in the Journal of Clinical Oncology.
For all cancer types, the incidence rate for CVD was 4.79 per 1,000 person-years; among comparison patients, the rate was 1.81 per 1,000 person-years. After adjustment for age, sex, ethnicity, cardiovascular risk factors (CVRF), smoking, and overweight/obesity, this yielded an incident rate ratio (IRR) of 2.37 (95% CI, 1.93–2.93; P < 0.01).
The study also analyzed by specific cancer types. The highest IRR was found in leukemia patients, at 4.23 (95% CI, 1.73–10.31; P < .01); breast cancer also yielded a high IRR at 3.63 (95% CI, 2.41–5.47; P < .01). Lymphoma and melanoma also had significantly elevated rates of CVD, while thyroid cancer’s IRR did not reach significance.
AYA cancers increased the risk of developing certain CVRFs as well. The IRR for diabetes among all cancer survivors was 1.48 (95% CI, 1.31–1.66; P < .01), and for dyslipidemia it was 1.17 (95% CI, 1.08–1.27; P < .01). The risk was not significantly elevated for developing hypertension.
A multivariate analysis showed that AYA cancer survivors who did develop CVD had a substantially higher risk of all-cause mortality compared to those with CVD; the adjusted hazard ratio was 10.9 (95% CI, 8.1–14.8; P < .01). The survival rate at 5 and 10 years after the index date (meaning, 7 and 12 years following cancer diagnosis) was 0.67 and 0.55, respectively, in cancer survivors who developed CVD, compared with 0.92 and 0.90 in those survivors without CVD.
“These data suggest that prevention needs to be emphasized across the full spectrum of cardiovascular disease development, starting from risk factors, and potentially with tailored CVD/CVRF screening schedules for survivors of AYA cancer,” the authors concluded. “Additional research is needed to understand the impact of AYA cancer treatment and the role of lifestyle risk/preventive factors in these cancer survivors.”