Are patients with stage III non-small cell lung cancer treated with chemoradiotherapy at risk for cardiac events? Results from a retrospective cohort study.

Objectives: Dyspnoea is one of the symptoms frequently encountered after treatment with chemoradiotherapy (CRT) in stage III non-small cell lung cancer (NSCLC). Long-term data on mild to moderately severe cardiac events as underlying cause of dyspnoea in patients with stage III NSCLC are lacking. Therefore, the incidence of new cardiac events, with a common terminology criteria for adverse events (CTCAE) score of ≥2 within 5 years after diagnosis, were analysed.

Design: Retrospective multicentre cohort study of patients with stage III NSCLC treated with CRT from 2006 to 2013. The medical files of the treated patients were reviewed.

Outcome Measures: The primary endpoint of the study was the incidence of new cardiac events with a CTCAE score of ≥2 within 5 years after diagnosis. Secondary endpoint was to identify risk factors associated with the development of a cardiac event.

Results: Four hundred and sixty patients were included in the study. Of all patients, 150 (32.6%) developed a new cardiac event. In patients with a known cardiac history (n=138), 44.2% developed an event. The most common cardiac events were arrhythmia (14.6%), heart failure (7.6%) and symptomatic coronary artery disease (6.8%). Pre-existent cardiac comorbidity (HR 1.96; p<0.01) and WHO-performance score ≥2 (HR 2.71; p<0.01) were significantly associated with developing a cardiac event. The majority of patients did not have pre-existent cardiac comorbidity (n=322). Elevated WHO/International Society of Hypertension score was not identified as a significant predictor for cardiac events.

Conclusion: One-third of patients with stage III NSCLC treated in daily clinical practice develop a new cardiac event within 5 years after CRT. All physicians confronted with patients with NSCLC should take cardiac comorbidity as a serious possible explanation for dyspnoea after treatment with CRT.