360P - Number of lymph nodes examined was not an independent risk factor for the survival of patients with stage IA1-2 lung adenocarcinoma undergoing sublobar resection

Background

To explore the relationship between the number of reginal lymph nodes (LNs) examined and prognosis among patients with stage IA1-2 lung adenocarcinoma (LUAD) who underwent sublobar resection.

Methods

A total of 690 patients with stage IA1-2 LUAD patients from 2004-2015 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. of which 475 were grouped into 05 cohort for the cutoff value calculated through X-tile software. Two groups were compared in terms of overall survival (OS) and lung cancer-specific survival (LCSS). Propensity score matched (PSM) comparative analysis and Cox regression analysis were conducted.

Results

Before PSM, the patients with more LNs examined exhibited better OS and LCSS (Figure 1A&B). The median OS for 0< LNE≤5 cohort patients was 116.0 months, that for LNE >5 was 124.0 months (p=0.012; HR: 1.472, 95%CI: 1.107-1.959). The median LCSS for two cohorts were both not reached, respectively (p=0.044; HR: 1.498, 95%CI: 1.021-2.197). After PSM, 209 pairs of patients were matched and all variables were well balanced. And comparable OS and LCSS were observed between two matched cohorts (Figure 1C&D). The median OS for 0< LNE≤5 cohort patients was 122.0 months, that for LNE >5 was 124.0 months (p=0.28; HR: 1.187, 95%CI: 0.820-1.720). The median LCSS for two cohorts were both not reached, respectively (p=0.90; HR: 0.997, 95%CI: 0.588-1.692). Univariate and multivariate cox regression analysis revealed that the number of regional (LNs) examined was not an independent risk factors for OS or LCSS (Table; p=0.126, HR: 0.767, 95%CI: 0.479-0.919; p=0.237, HR: 0.773, 95%CI: 0.503-1.185).

Conclusions

The number of regional LNs examined did not correlate with the survival prognosis for stage IA1-2 lung adenocarcinoma patients who underwent sublobar resection.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Key Lab System Project of Guangdong Science and Technology Department-Guangdong Provincial Key Lab of Translational Medicine in Lung Cancer (Grant No. 2017B030314120), Project of National Natural Science Foundation (Grant Nos. 81673031, 81872510), Research Fund from Guangzhou Science and Technology Bureau (Grant No. 201704020161), High-Level Hospital Construction Project (Grant No. DFJH201801), and Guangdong Provincial People’s Hospital Young Talent Project (Grant No. GDPPHYTP201902).

Disclosure

All authors have declared no conflicts of interest.