Impact of number of lymph nodes (LN) examined at the time of surgical resection (Sx) on the survival of stage IA non-small cell lung cancer (NSCLC) patients (pts)

Abstract

7534 Background: Despite complete Sx pts with stage IA have an approx. 5yr survival of only 61%. Better prognostic factors need to be identified in this stage. In this study we evaluated the effect of detailed surgical LN exam on Progression Free Survival (PFS) and Overall Survival (OS) of these pts. Methods: All pts with pT1pN0M0 (stage IA) NSCLC from 11/2000 to 12/2006 at OSF Saint Francis Medical Center, Peoria, IL were deemed eligible. Log rank and Cox proportional hazard model (CPHM) was used to estimate survival rates and relative risks. For the purpose of analyses, number of LN examined was broken down in 4 groups; 1–3 (group1or G1), 4–6 (G2), 7–9 (G3), > 9 lymph nodes (G4). Results: Of the 112 eligible pts, analyses were performed on 98 pts with complete data on pathologic tumor stage, number of LN, grade, differentiation and race. Demographics are as follows: median age: 71 (33–83 yrs), median follow-up time: 2.08 years (0.07–5.31 yrs). LN groups pts numbers: G1: 33 (33.7%) pts, G2; 33 (33.7%) pts, G3: 19 (19.3%) and G4: 13 (13.3%). We observed a statistically significant increasing trend in PFS with increase in number of LN examined (Log Rank p-value=0.039). No significant trend in OS was observed with increase in number of LN (log-rank p-value=0.2). 4 yr PFS for G1, G2, G3, G4 was18.1%, 67.9%, 52.6%, 72.7%. 4 yr OS for G1, G2, G3, G4 was 38.3%, 73.8%, 52.6%, 87.5%. CPHM demonstrated an increase in survival of G2, G3 and G4 as compared to G1 (PF Hazard ratios: 0.37, 0.53, 0.26; Overall Hazard Ratios: 0.44, 0.74 and 0.33 respectively). Conclusions: This data suggests that there is a significant increase in PFS survival with increase in number of LN examined at surgery in stage IA NSCLC pts. No significant financial relationships to disclose.