Cardiac Events After Radiotherapy for Locally Advanced Lung Cancer
An analysis of patients from 4 prospective radiotherapy trials for locally advanced non–small cell lung cancer (NSCLC) conducted at 2 centers in Michigan showed that grade ≥ 3 cardiac events occurred in more than 10% of patients. The study was reported by Dess et al in the Journal of Clinical Oncology.
Study Details
The study included 125 patients with stage II to III disease treated at the University of Michigan and Ann Arbor Veterans Affairs Hospital between 2004 and 2013. Median follow-up was 51 months for surviving patients. The median radiotherapy dose was 70 Gy, with 84% of patients receiving concurrent chemotherapy, and 27% had preexisting cardiac disease.
Risk of Cardiac Events
In total, 19 patients (15%) had a grade ≥ 3 cardiac event at a median of 11 months, with a 24-month cumulative incidence of 11% (95% confidence interval [CI] = 5%–16%). On a multivariable analysis, risk of grade ≥ 3 events was significantly increased with preexisting cardiac disease (hazard ratio [HR] = 2.96, P = .04) and an increased mean heart dose (HR = 1.07/Gy, P = .01).
When included as time-dependent variables on the multivariate analysis, both disease progression (n = 71; HR = 2.15, 95% CI = 1.54–3.00) and grade ≥ 3 cardiac events (HR = 1.76, 95% CI = 1.04–2.99) were associated with poorer overall survival.
The investigators concluded: “The 24-month cumulative incidence of grade 3 cardiac events exceeded 10% among patients with locally advanced NSCLC treated with definitive radiation. Preexisting cardiac disease and higher mean heart dose were significantly associated with higher cardiac event rates. Caution should be used with cardiac dose to minimize risk of radiation-associated injury. However, cardiac risks should be balanced against tumor control, given the unfavorable prognosis associated with disease progression.”
The study was supported by grants from the National Institutes of Health.
Shruti Jolly, MD, of the Department of Radiation Oncology, University of Michigan School of Medicine, is the corresponding author of the Journal of Clinical Oncology article.
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®.
