Donglai Chen1, Yiming Mao2, Junmiao Wen3,4, Jian Shu5,6, Fei Ye5,7, Yunlang She1, Qifeng Ding5, Li Shi5, Tao Xue8, Min Fan3,4, Yongbing Chen5, Chang Chen1. 1. 1Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai. 2. 2Department of Thoracic Surgery, Suzhou Kowloon Hospital Shanghai Jiaotong University School of Medicine, Suzhou. 3. 3Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai. 4. 4Department of Oncology, Shanghai Medical College, Fudan University, Shanghai. 5. 5Department of Thoracic Surgery, the Second Affiliated Hospital of Soochow University, Suzhou. 6. 6Department of Thoracic Surgery, Taicang Affiliated Hospital of Soochow University, the First People's Hospital of Taicang, Taicang. 7. 7Department of Thoracic Surgery, Hai'an Hospital Affiliated to Nantong University, Hai'an; and. 8. 8Department of Cardiothoracic Surgery, Zhongda Hospital Southeast University, Nanjing, China.
Abstract
BACKGROUND: This study sought to determine the optimal number of examined lymph nodes (ELNs) and examined node stations (ENSs) in patients with radiologically pure-solid non-small cell lung cancer (NSCLC) who underwent lobectomy and ipsilateral lymphadenectomy by investigating the impact of ELNs and ENSs on accurate staging and long-term survival. MATERIALS AND METHODS: Data from 6 institutions in China on resected clinical stage I-II (cI-II) NSCLCs presenting as pure-solid tumors were analyzed for the impact of ELNs and ENSs on nodal upstaging, stage migration, recurrence-free survival (RFS), and overall survival (OS). Correlations between different endpoints and ELNs or ENSs were fitted with a LOWESS smoother, and the structural break points were determined by Chow test. RESULTS: Both ELNs and ENSs were identified as independent prognostic factors for OS (ENS hazard ratio [HR], 0.690; 95% CI, 0.597-0.797; P<.001; ELN HR, 0.950; 95% CI, 0.917-0.983; P=.004) and RFS (ENS HR, 0.859; 95% CI, 0.793-0.931; P<.001; ELN HR, 0.960; 95% CI, 0.942-0.962; P<.001), which were also associated with postoperative nodal upstaging (ENS odds ratio [OR], 1.057; 95% CI, 1.002-1.187; P=.004; ELN OR, 1.186; 95% CI, 1.148-1.226; P<.001). A greater number of ELNs and ENSs correlated with a higher accuracy of nodal staging and a lower probability of stage migration. Cut-point analysis revealed an optimal cutoff of 18 LNs and 6 node stations for stage cI-II pure-solid NSCLCs, which were validated in our multi-institutional cohort. CONCLUSIONS: Extensive examination of LNs and node stations seemed crucial to predicting accurate staging and survival outcomes. A threshold of 18 LNs and 6 node stations might be considered for evaluating the quality of LN examination in patients with stage cI-II radiologically pure-solid NSCLCs.
BACKGROUND: This study sought to determine the optimal number of examined lymph nodes (ELNs) and examined node stations (ENSs) in patients with radiologically pure-solid non-small cell lung cancer (NSCLC) who underwent lobectomy and ipsilateral lymphadenectomy by investigating the impact of ELNs and ENSs on accurate staging and long-term survival. MATERIALS AND METHODS: Data from 6 institutions in China on resected clinical stage I-II (cI-II) NSCLCs presenting as pure-solid tumors were analyzed for the impact of ELNs and ENSs on nodal upstaging, stage migration, recurrence-free survival (RFS), and overall survival (OS). Correlations between different endpoints and ELNs or ENSs were fitted with a LOWESS smoother, and the structural break points were determined by Chow test. RESULTS: Both ELNs and ENSs were identified as independent prognostic factors for OS (ENS hazard ratio [HR], 0.690; 95% CI, 0.597-0.797; P<.001; ELN HR, 0.950; 95% CI, 0.917-0.983; P=.004) and RFS (ENS HR, 0.859; 95% CI, 0.793-0.931; P<.001; ELN HR, 0.960; 95% CI, 0.942-0.962; P<.001), which were also associated with postoperative nodal upstaging (ENS odds ratio [OR], 1.057; 95% CI, 1.002-1.187; P=.004; ELN OR, 1.186; 95% CI, 1.148-1.226; P<.001). A greater number of ELNs and ENSs correlated with a higher accuracy of nodal staging and a lower probability of stage migration. Cut-point analysis revealed an optimal cutoff of 18 LNs and 6 node stations for stage cI-II pure-solid NSCLCs, which were validated in our multi-institutional cohort. CONCLUSIONS: Extensive examination of LNs and node stations seemed crucial to predicting accurate staging and survival outcomes. A threshold of 18 LNs and 6 node stations might be considered for evaluating the quality of LN examination in patients with stage cI-II radiologically pure-solid NSCLCs.