Add-on radiation therapy poses higher cardiovascular risk in stage III NSCLC

The addition of radiation therapy to chemotherapy may be more detrimental than beneficial in patients with resectable stage III nonsmall‐cell lung cancer (NSCLC), being associated with a heightened risk of severe cardiac events, as shown in a study.

The study used data from the Surveillance, Epidemiology and End Results‐Medicare database and included patients aged ≥66 years, had stage IIIA/B resectable NSCLC, and received adjuvant or neoadjuvant chemotherapy or chemoradiation within 121 days of diagnosis.

Propensity score facilitated matching of patients who underwent chemoradiation to those who received chemotherapy only. All of them were followed from day 121 to first cardiac outcome, noncardiac death, radiation initiation by patients who received chemotherapy only, fee‐for‐service enrolment interruption, or the end of the study (31 December 2016).

The primary endpoint was the first of the following severe cardiac events: acute myocardial infarction, other hospitalized ischaemic heart disease, hospitalized heart failure, percutaneous coronary intervention/coronary artery bypass graft, cardiac death, or urgent/inpatient care for pericardial disease, conduction abnormality, valve disorder, or ischaemic heart disease.

Over a median follow‐up of 13 months, a severe cardiac event occurred in 70 of 682 patients who received chemoradiation (10.26 percent) and 43 of 682 matched patients who received chemotherapy only (6.30 percent), with the difference being statistically significant (p=0.008). The median time to first event was 5.45 months.

Chemoradiation was associated with a higher rate of severe cardiac events (cause‐specific HR, 1.62, 95 percent confidence interval [CI], 1.11–2.37; subdistribution HR, 1.41, 95 percent CI, 0.97–2.04).

Furthermore, patients who received chemoradiation vs chemotherapy only appeared to have greater disease severity (noncardiac death cause‐specific HR, 2.53, 95 percent CI, 1.93–3.33; subdistribution HR, 2.52, 95 percent CI, 1.90–3.33).