Association between forced expiratory volume in 1 s and relapse-free survival in operable non-small cell lung cancer: a prospective cohort study with propensity score overlap weighting.

Objectives: Investigate the correlation between the percentage of predicted forced expiratory volume in 1 s (FEV1%pred) and survival outcomes, namely relapse-free survival (RFS) and overall survival (OS), in patients diagnosed with operable early-stage non-small cell lung cancer (NSCLC).

Design: Prospective observational study.

Setting: Clinical settings in Xiangya Hospital, Central South University, Hunan, China.

Participants: From November 2014 to December 2019, 775 operable patients with NSCLC, median age 58 years (IQR 13) with 40.6% women, were consecutively enrolled and underwent preoperative FEV1 assessment. All participants were evaluated using the FEV1%pred assessment. Subsequent treatments and operative interventions followed established protocols for NSCLC.

Results: During the follow-up, which lasted a median of 40 months (range 1-85 months) and continued until December 2021, 202 patients either relapsed or died. Optimal FEV1%pred cut-off was identified using receiver operating characteristic analysis. Results revealed 110 and 71 relapses and deaths per 1000 person-years for patients with FEV1 values of <82%pred and ≥82%pred, respectively. Cox proportional hazards models, adjusted for demographics, medical history and surgery characteristics with propensity score overlap weighting, revealed the significant impact of lower FEV1%pred on decreased RFS and OS. An FEV1%pred less than 82% displayed a significant association with decreased RFS (weighted HR, 1.55; 95% CI, 1.14 to 2.09; p=0.007) and OS (weighted HR, 1.50; 95% CI, 1.01 to 2.23; p=0.04).

Conclusions: Lower FEV1%pred values notably correlate with compromised RFS and OS in individuals operable for early-stage NSCLC, suggesting that FEV1%pred may serve as a valuable tool in evaluating and managing long-term recurrence risk in patients with early-stage NSCLC.

Trial Registration Number: ChiCTR2100048120.