Impact of examined lymph node counts on survival of patients with stage IA non-small cell lung cancer undergoing sublobar resection.

BACKGROUND

The correlation between the number of examined lymph nodes (ELNs) and lung cancer-specific survival (LCSS) of stage IA non-small cell lung cancer (NSCLC) patients, who underwent sublobar resection in which lymph node (LN) sampling was relatively restricted as compared with standard lobectomy remains unclear.

METHODS

Patients from the Surveillance, Epidemiology, and End Results database with stage IA NSCLC who underwent sublobar resection were categorized based on ELN count (1-6 ≥7; the cut point 7 was identified by Cox model).

RESULTS

Collectively, 3,219 patients with a median follow-up time of 37 months were included in this study (G1: 1-6 ELN, n=2,410; G2: ≥7 ELN, n=809). The 5-year LCSS rate of the G1 and G2 cohorts were 75% and 83%, respectively. Cox analysis suggested that the LCSS of G1 cohort patients was lower as compared with the G2 cohort [hazard ratio (HR) =1.530; 95% confidence interval (CI): 1.240-1.988, P<0.001). Propensity score analysis also showed decreased survival of the matched G1 cohort (HR =1.499; 95% CI: 1.176-1.911; P=0.001).

CONCLUSIONS

The data suggested the ELNs ≤6 were associated with poor prognoses. Adequate LN sampling is essential even for stage IA NSCLC patients undergoing sublobar resection.