title: A Proposal for Combination of Lymph Node Ratio and Anatomic Location of Involved Lymph Nodes for Nodal Classification in Non-Small Cell Lung Cancer.
abstract: The current pathologic nodal classification (pN) based on anatomic location of involved lymph nodes (LNs) is unsatisfactory in distinguishing heterogeneous pN1 or pN2 non-small cell lung cancer (NSCLC). For the first time we comprehensively compared the prognostic significance of the number of positive LNs (nN), the ratio of the number of positive to removed LNs (LN ratio [LNR]), the combination of pN and nN (pN-nN), the combination of pN and LNR (pN-LNR), and pN to identify a superior classification.
  
  
  
  We identified 700 patients with pN1 (n = 203) or pN2 (n = 497) NSCLC. We classified the patients into four nN categories (nN1, nN2, nN3-6, and nN≥7), four pN-nN categories (pN1-nN1-2, pN1-nN≥3, pN2-nN1-6, and pN2-nN≥7); four LNR categories (LNR≤0.05, 0.1≥LNR>0.05, 0.4≥LNR>0.1, and LNR>0.4), and four pN-LNR categories (pN1-LNR<0.1, pN1-LNR≥0.1, pN2-LNR<0.4, and pN2-LNR≥0.4). The log-rank test was used to analyze differences among groups, and Cox regression was used to evaluate relationships between each classification and survival.
  
  
  
  In adjusted analyses, pN-LNR was an independent prognostic factor for patients with pN1 or pN2 NSCLC, as were pN-nN, LNR, nN, and pN. pN-LNR was prognostically superior to the other four classifications. Postoperative radiotherapy (PORT) was an independent prognostic factor for pN2 NSCLC. Analyses stratified by LNR showed that PORT did not improve survival in patients with pN2-LNR<0.14 NSCLC, whereas significantly improved survival times in pN2-LNR≥0.14 NSCLC.
  
  
  
  We propose a potential revised nodal classification, pN-LNR, to further stratify patients with pN1 or pN2 NSCLC into subgroups so as to more precisely predict survival and help tailor individualized postoperative treatment.
authors.affiliation: Cancer Center, Shandong Provincial Hospital Affiliated with Shandong University, Jinan, People's Republic of China; Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ding
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Zhouguang
authors.initials: Z
authors.lastname: Hui
authors.affiliation: Cancer Center, Shandong Provincial Hospital Affiliated with Shandong University, Jinan, People's Republic of China; Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Honghai
authors.initials: H
authors.lastname: Dai
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Men
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jima
authors.initials: J
authors.lastname: Lv
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Zongmei
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Qinfu
authors.initials: Q
authors.lastname: Feng
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Zefen
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Dongfu
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Weibo
authors.initials: W
authors.lastname: Yin
authors.affiliation: Department of Pathology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Lu
authors.affiliation: Department of Thoracic Surgery, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. Electronic address: wlhwq@yahoo.com.
authors.forename: Luhua
authors.initials: L
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000145:classification / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification / Q000401:mortality / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models
keywords: Lymph node ratio; Non–small cell lung cancer; Pathologic nodal classification; Prognosis