Jie Dai1, Ming Liu1, Yang Yang1, Qiuyuan Li1, Nan Song1, Gaetano Rocco2, Alan D L Sihoe3, Diego Gonzalez-Rivas4, Hon Chi Suen5, Wenxin He1, Liang Duan1, Jiang Fan1, Deping Zhao1, Haifeng Wang1, Yuming Zhu1, Chang Chen1, Robert B Diasio6, Gening Jiang1, Ping Yang7, Peng Zhang8. 1. Department of Thoracic Surgery, Shanghai Pulmonary Hospital Tongji University, Shanghai, People's Republic of China. 2. Thoracic Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York. 3. Department of Thoracic Surgery, Shanghai Pulmonary Hospital Tongji University, Shanghai, People's Republic of China; Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of China; Division of Thoracic Surgery, The University of Hong Kong Shenzhen Hospital, Shenzhen, People's Republic of China. 4. Department of Thoracic Surgery, Shanghai Pulmonary Hospital Tongji University, Shanghai, People's Republic of China; Department of Thoracic Surgery, Coruña University Hospital, Coruña, Spain. 5. Center for Cardiothoracic Surgery, Inc., St. Louis, Missouri. 6. Mayo Clinic Cancer Center, Rochester, Minnesota. 7. Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, Minnesota. 8. Department of Thoracic Surgery, Shanghai Pulmonary Hospital Tongji University, Shanghai, People's Republic of China. Electronic address: zhangpeng1121@tongji.edu.cn.
Abstract
OBJECTIVE: To determine the optimal number of lymph nodes (LNs) examined and the role of adjuvant chemotherapy in stage I lung cancer. METHODS: The National Cancer Database was queried for surgically treated patients with pathologic stage I lung cancer between 2006 and 2014 (N = 65,438). The optimal LN numbers were determined in the multivariate Cox model and were further validated in the cohort with clinical stage I disease (N = 117,112) in terms of nodal upstaging and prognostic stratification. The role of adjuvant chemotherapy in patients with suboptimal staging (number of LNs examined was less than than the optimum) was evaluated in each T stage. RESULTS: The number of LNs examined correlated with tumor size (p < 0.001). There were increasing survival benefits with each additional LN examined-up to eight, nine, 10, and 11 nodes for patients with T1a, T1b, T1c, and T2a, respectively. Validation from the cohort with clinically staged disease showed that the threshold of eight to 11 LNs was an independent predictor of nodal upstaging (OR = 1.706, 95% confidence interval [CI] 1.608-1.779) and survival outcome (hazard ratio = 0.890, 95% CI: 0.865-0.916). After propensity matching, adjuvant chemotherapy was associated with improved survival in patients with stage T2a disease having suboptimal staging (hazard ratio = 0.841, 95% CI: 0.714-0.990), but not in patients with stage T1a to T1c disease. CONCLUSION: LN evaluation was important for accurate staging and adequate treatment, and examinations of an increasing number of nodes for progressively higher T components (i.e., eight, nine, 10, and 11 nodes for T1a, T1b, T1c, and T2a tumors, respectively) seemed crucial to predict upstaging and survival outcomes. Adjuvant chemotherapy might be beneficial to patients with stage T2a disease who have suboptimal nodal staging.
OBJECTIVE: To determine the optimal number of lymph nodes (LNs) examined and the role of adjuvant chemotherapy in stage I lung cancer. METHODS: The National Cancer Database was queried for surgically treated patients with pathologic stage I lung cancer between 2006 and 2014 (N = 65,438). The optimal LN numbers were determined in the multivariate Cox model and were further validated in the cohort with clinical stage I disease (N = 117,112) in terms of nodal upstaging and prognostic stratification. The role of adjuvant chemotherapy in patients with suboptimal staging (number of LNs examined was less than than the optimum) was evaluated in each T stage. RESULTS: The number of LNs examined correlated with tumor size (p < 0.001). There were increasing survival benefits with each additional LN examined-up to eight, nine, 10, and 11 nodes for patients with T1a, T1b, T1c, and T2a, respectively. Validation from the cohort with clinically staged disease showed that the threshold of eight to 11 LNs was an independent predictor of nodal upstaging (OR = 1.706, 95% confidence interval [CI] 1.608-1.779) and survival outcome (hazard ratio = 0.890, 95% CI: 0.865-0.916). After propensity matching, adjuvant chemotherapy was associated with improved survival in patients with stage T2a disease having suboptimal staging (hazard ratio = 0.841, 95% CI: 0.714-0.990), but not in patients with stage T1a to T1c disease. CONCLUSION: LN evaluation was important for accurate staging and adequate treatment, and examinations of an increasing number of nodes for progressively higher T components (i.e., eight, nine, 10, and 11 nodes for T1a, T1b, T1c, and T2a tumors, respectively) seemed crucial to predict upstaging and survival outcomes. Adjuvant chemotherapy might be beneficial to patients with stage T2a disease who have suboptimal nodal staging.