Minimally Invasive Lobectomy Is Associated With Lower Noncancer-specific Mortality in Elderly Patients: A Propensity Score Matched Competing Risks Analysis

OBJECTIVE: To investigate cancer lobectomy by minimally invasive surgery (MIS) versus open thoracotomy in elderly patients with nonsmall cell lung cancer (NSCLC). BACKGROUND: Two-thirds of patients with NSCLC are >/=65 years of age. As age increases, the risk of competing events, such as noncancer death, also increases. METHODS: Elderly patients (>/=65 yrs of age) who have undergone curative-intent lobectomy for stage I-III NSCLC without induction therapy (2002-2013) were included (n=1,303). Of those, 607 patients had undergone MIS and 696 had undergone thoracotomy. Propensity-score matching was performed to identify pairs of thoracotomy and MIS patients with comparable clinical characteristics (eg, year of surgery, comorbidities, and pulmonary function). Association between surgical approach (MIS vs thoracotomy) and lung cancer-specific and noncancer-specific cumulative incidence of death (CID) was analyzed using competing risks approach. RESULTS: Following propensity score matching of patients who had undergone thoracotomy (n=338) versus MIS (n=338), MIS was associated with shorter length of stay (P <0.001), lower noncancer-specific 1-year mortality (P=0.027), and lower noncancer-specific CID (P=0.014) compared with thoracotomy; there was no difference in lung cancer-specific CID between surgical approaches. On multivariable analysis, thoracotomy was a significant risk factor for noncancer-specific death (subhazard ratio 2.45, 95% CI 1.18-5.06, P=0.016) independent of age, sex, and diffusion capacity of the lungs for carbon monoxide. CONCLUSION: In a propensity score-matched cohort, multivariable analysis has indicated that lobectomy performed by MIS is associated with lower incidence of noncancer-specific mortality compared with lobectomy performed by open thoracotomy in elderly patients with NSCLC.