Role of stereotactic body radiotherapy for early-stage non-small-cell lung cancer in patients borderline for surgery due to impaired pulmonary function.

Abstract

Stereotactic body radiotherapy (SBRT) is recommended only for inoperable patients with early-stage (e-stage) non-small-cell lung cancer (NSCLC). We compared outcomes between surgery and SBRT in patients borderline for surgery due to impaired pulmonary function (PF). We reviewed single-institution retrospective data of 578 patients with clinically T1-2N0M0 NSCLC treated by surgery or SBRT between 2004 and 2014, and extracted a cohort with borderline impaired PF for surgery, which was defined as predicted postoperative (PPO) forced expiratory volume in 1 s (FEV1 ) of<50% and ≥30%. Overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) were compared between surgery and SBRT using propensity score-matching (PSM) to avoid bias. Among a total of 116 eligible patients with a median PPO FEV1 of 45%, PSM identified 25 patients from each group with similar characteristics. The median age, pretreatment FEV1 , and follow-up durations for the surgery and SBRT groups were 75 and 74 years, 58% and 56%, and 56 and 60 months, respectively. The 5-year OS, CSS, and DFS rates of the surgery versus SBRT groups were 60%versus 63%, 76%versus 81%, and 52%versus 48%, respectively (p=0.97, 0.81, and 0.99). The surgical mortality was 4.0%, but no treatment-related death was observed after SBRT. The incidence of ≥ grade 2 adverse events after surgery was double that after SBRT (40%versus 20%, p=.22). Our study suggests that SBRT is a reasonable option for patients with e-stage NSCLC and impaired PF who are considered borderline candidates for surgery.