Competing Risk Analysis in Lung Cancer Patients Over 80 Years Old Undergoing Surgery.

BACKGROUND: This study aimed to analyze cause-specific mortality in lung cancer patients over 80 years old undergoing surgery. METHODS: This retrospective, multi-institutional analysis included patients aged ≥ 80 years who underwent radical surgery for primary lung cancer from January 1998 to December 2015. Preoperative clinical data, surgical results, survival, and cause of death were evaluated. Competing risk analysis for cause-specific mortality was performed. RESULTS: Of the 337 patients (median age 82 years) enrolled and analyzed, 68.1% were male. There were 52 and 44 cancer-specific and non-cancer-specific deaths, respectively. On competing risk regression analysis, non-cancer-specific deaths were significantly associated with male sex (hazard ratio [HR]: 3.06, 95% confidence interval [CI]: 1.02-9.12, p = 0.046), coronary artery disease (HR: 2.49, 95% CI: 2.49 [1.14-5.47], p = 0.02), interstitial pneumonia (HR: 3.58, 95% CI: 1.73-7.40, p < 0.001), and pathological stage III (HR: 3.83, 95% CI: 1.44-10.13, p = 0.007). In contrast, cancer-specific deaths were significantly associated with limited resection (HR: 1.99, 95% CI: 1.02-3.89, p = 0.04) and pathological stage III (HR: 3.13, 95% CI: 1.44-6.80, p = 0.004). The 5-year cumulative incidences of lung cancer-specific and non-cancer-specific deaths were 18.0% and 15.9%, respectively. CONCLUSIONS: Prognostic factors for non-cancer-specific death were different from those of cancer-specific death, except for pathological stage. Each prognostic factor should be considered when deciding surgical indication and procedure and monitoring for pulmonary events during outpatient follow-up.