High cardiac radiation dose may increase mortality odds in patients with lung cancer
Among patients with non-small cell lung cancer, a higher cardiac radiation dose may lead to elevated risk for major adverse cardiac events and all-cause mortality, according to findings published in the Journal of the American College of Cardiology.
Katelyn M. Atkins, MD, PhD, and colleagues investigated whether cardiac radiation dose was a predictor of major adverse cardiac events and all-cause mortality.
“This is alarming data — to think that 1 in 10 of the patients I’m treating for this type of cancer will go on to have a heart attack or other major cardiac event,” Raymond Mak, MD, a thoracic radiation oncologist at the department of radiation oncology, Dana-Farber Cancer Institute and Brigham and Women’s Hospital, said in a press release. “These cardiac events are happening earlier and more often than previously thought. More patients are living long enough to experience this risk of cardiac toxicity. We need to start paying attention to this and working together with cardiologists to help these patterns.”
Measuring mean radiation dose
The researchers performed a retrospective analysis that included 748 consecutive patients with locally advanced non-small cell lung cancer (median age, 65 years; 49% women) who were treated with thoracic radiotherapy.
Over a median follow-up of 20.4 months, Atkins, a resident in the Harvard Radiation Oncology Residency Program, Dana-Farber Cancer Center Institute and Brigham and Women’s Hospital, and colleagues found that 77 patients developed one or more major adverse cardiac events, defined as cardiac death, MI, unstable angina, HF hospitalization or urgent visit and coronary revascularization (2-year cumulative incidence = 5.8%; 95% CI, 4.3-7.7) and 533 patients died.
Mean radiation dose delivered to the heart was associated with significantly increased risk for major adverse cardiac events (adjusted HR = 1.05/Gy; 95% CI, 1.02-1.08) and all-cause mortality (aHR = 1.02/Gy; 95% CI, 1-1.03), the researchers wrote.
Mean heart dosage ( 10 Gy vs. < 10 Gy) was associated with significantly increased risk for all-cause mortality in CHD-negative patients (178 vs. 118 deaths; HR = 1.34; 95% CI, 1.06-1.69), Atkins and colleagues wrote.
Mean heart dose of at least 10 Gy did not confer a significant increased risk for death in CHD-positive patients (112 vs. 82 deaths; HR = 0.94; 95% CI, 0.7-1.25), the researchers wrote.
Improving and optimizing treatment
Atkins and colleagues wrote that the study’s results highlight the importance of early recognition and treatment of CV events.
“When treating patients with lung cancer, it’s a balance of risks,” Atkins said in the release. “But we need to start thinking about where there’s room for improvement in optimizing treatment for patients and room for improvement in terms of collaborating with primary care physicians and cardiologists.” - by Earl Holland Jr.
Disclosures: Atkins reports no relevant financial disclosures. Mak reports he serves on the scientific advisory board of AstraZeneca and has received honorarium from NewRT. Please see the study for all other authors’ relevant financial disclosures.