Risk of clinically significant cardiovascular disease associated with postoperative radiotherapy in non-small cell lung cancer patients receiving surgical resection followed by adjuvant chemotherapy: A Korean nationwide cohort study.

BACKGROUND: There are no large-scale datasets that analyze the relationship between postoperative radiotherapy (PORT) and various cardiovascular diseases (CVDs) in patients with locally advanced non-small cell lung cancer (NSCLC). Therefore, we aimed to investigate the incidences of CVDs with PORT using a national population-based database.

METHODS: Patients diagnosed with NSCLC who underwent curative surgery followed by adjuvant chemotherapy were included from 2007 to 2017. Patients with a prior diagnosis of heart failure (HF), atrial fibrillation (AFib), or heart surgery were excluded. A total of 11,141 patients were included in the final analysis. PORT was used in 1334 patients. Most patients received lobectomy with mediastinal lymph node dissection.

RESULTS: Major adverse cardiac events mostly occurred within 3-4 years from the diagnosis. After the median follow-up duration of 70.6 months, HF was the most diagnosed disease (5.3 %), followed by AFib (4.5 %), stroke (4.1 %), and pulmonary embolism (3.5 %). All the incidences of clinically significant CVDs did not differ by PORT. This result remained unchanged after the propensity score matching comparison. Age ≥ 65, underlying hypertension, and history of ischemic heart disease were the most related factors to the occurrence of HF and AFib. No significant difference in CVD-free survivals according to PORT status was observed. When stratified by proposed scoring, there were no subgroups showed increased incidence by PORT.

CONCLUSIONS: These results suggest that PORT had no significant impact on various CVD occurrences in NSCLC patients without underlying heart disease.