Second primary lung cancer and treatment strategy after lobectomy vs. segmentectomy for first primary lung cancer

Segmentectomy is now widely accepted as standard treatment for early-stage non-small cell lung cancer (NSCLC). Given the recognized risk of second primary lung cancer (SPLC), lung preservation may affect long-term management. This study evaluates the incidence of SPLC and compares subsequent treatment strategies following lobectomy versus segmentectomy for first primary lung cancer (FPLC).

We conducted a single-institution, retrospective study of patients who underwent lobectomy or segmentectomy for clinical T1N0M0 NSCLC between 2013 and 2022. Patients diagnosed with SPLC after FPLC were included. The primary outcomes were SPLC incidence and overall survival.

Of 1,363 patients (lobectomy: 954, segmentectomy: 409), 150 (11.0%) developed SPLC over a median 90.5-month follow-up. Five-year SPLC incidence varied by smoking status (non-smokers: 3.9%, past: 11.1%, current: 17.9%; P=0.003). Among SPLC patients, the median interval from FPLC to SPLC was 37.0 months. Pulmonary function changes between FPLC and SPLC workups were similar between groups [forced expiratory volume in 1 second (FEV₁)%: -4.5% vs. -5.0%, P=0.56; diffusing capacity of the lung for carbon monoxide (DLCO)%: -7.0% vs. -5.5%, P=0.29]. Surgical resection for SPLC was performed in 41 lobectomy patients and 25 segmentectomy patients (41.4% vs. 49.0%, P=0.39), with lower anatomic resection rates in the lobectomy group (53.7% vs. 88.0%, P=0.006). Five-year overall survival did not differ significantly, either from FPLC (83.2% vs. 84.3%; P=0.87) or SPLC diagnosis (48.0% vs. 56.1%; P=0.47).

Segmentectomy for FPLC was associated with a higher likelihood of anatomic resection for SPLC. Given the high incidence of SPLC, segmentectomy may benefit smokers by preserving future treatment options.