A large real-world cohort study of examined lymph node standards for adequate nodal staging in early non-small cell lung cancer

Zhihua Zhu; Zhengbo Song; Wenjie Jiao; Weijian Mei; Chunwei Xu; Qinghua Huang; Chaolun An; Jianguang Shi; Wenxian Wang; Guiping Yu; Pingli Sun; Yinbin Zhang; Jianfei Shen; Yong Song; Jun Qian; Wang Yao; Han Yang; written on behalf of AME Lung Cancer Collaborative Group

doi:10.21037/tlcr-20-1024

A large real-world cohort study of examined lymph node standards for adequate nodal staging in early non-small cell lung cancer

Transl Lung Cancer Res. 2021 Feb;10(2):815-825. doi: 10.21037/tlcr-20-1024.

Authors

Zhihua Zhu¹, Zhengbo Song², Wenjie Jiao³, Weijian Mei¹, Chunwei Xu⁴, Qinghua Huang⁵, Chaolun An⁶, Jianguang Shi⁷, Wenxian Wang², Guiping Yu⁸, Pingli Sun⁹, Yinbin Zhang¹⁰, Jianfei Shen¹¹, Yong Song¹², Jun Qian¹³, Wang Yao¹⁴, Han Yang¹; written on behalf of AME Lung Cancer Collaborative Group

Affiliations

¹ Sun Yat-sen University Cancer Center; State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
² Cancer Hospital of University of Chinese Academy of Sciences; Zhejiang Cancer Hospital, Hangzhou, China.
³ Affiliated Hospital of Qingdao University, Qingdao, China.
⁴ Fujian Cancer Hospital, Fuzhou, China.
⁵ Affiliated Tumor Hospital of Guangxi Medical University, Nanning, China.
⁶ Nantong Third People's Hospital, Nantong University, Nantong, China.
⁷ Ningbo First Hospital of Zhejiang University, Ningbo, China.
⁸ Affiliated Jiangyin Hospital of Southeast University, Jiangyin, China.
⁹ The Second Hospital of Jilin University, Changchun, China.
¹⁰ The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, China.
¹¹ Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, Linhai, China.
¹² Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
¹³ Southern Medical University, Guangzhou, China.
¹⁴ The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Abstract

Background: The current National Comprehensive Cancer Network (NCCN) guidelines for non-small cell lung cancer (NSCLC) recommend that surgeons sample is not clear. We aimed to define a minimal number of examined lymph nodes for removal or sampling for optimized nodal staging recommendation, with a focus on T_1-3N₀M₀ patients.

Methods: A total of 55,101 consecutive patients were selected, including 52,099 patients with US Surveillance, Epidemiology, and End Results (SEER) data and 3,002 patients in a Chinese multicenter database from 11 thoracic referral centers, who underwent complete resection plus lymph node dissection or sampling for stage T_1-3N₀M₀ NSCLC. Propensity score-matching analysis was performed with R software, and a cut-off value was calculated using X-tile software. Survival was evaluated using the Kaplan-Meier method and Cox proportional hazard models.

Results: Five-year survival rates with respect to total examined lymph nodes numbers (examined lymph nodes <10 vs. examined lymph nodes ≥10) were 69% and 64% (group A), 66% and 63% (group B), 62% and 58% (group C), 81% and 75% (group D). There were significant differences between examined lymph nodes <10 and examined lymph nodes >10 in each group (P<0.001).

Conclusions: A minimum of 10 examined lymph nodes would significantly improve T_1-3N₀M₀ NSCLC prognosis and patients' survival rates if implemented as a minimum standard for lymphadenectomy. Therefore, we recommended a minimum of 10 examined lymph nodes for T_1-3N₀M₀ patients.

Keywords: Non-small cell lung cancer (NSCLC); cohort study; examined lymph node (ELN); minimal number; nodal staging.