title: Prognostic Significance of the Number of Metastatic pN2 Lymph Nodes in Stage IIIA-N2 Non-Small-Cell Lung Cancer After Curative Resection.
abstract: Stage IIIA-N2 non-small cell lung cancer (NSCLC) shows prognostic heterogeneity. We investigated the prognostic relevance of the number of metastatic pN2 nodes in patients with IIIA-N2 NSCLC. The criteria for the number of pN2 used in this study were significantly associated with the survival outcomes after surgery and may improve the accuracy of prognostic prediction in this subgroup of patients.
  
  
  BACKGROUND
  There have been controversies regarding the prognostic relevance of the number of positive N2 nodes in pathologic stage IIIA-N2 non-small-cell lung cancer (NSCLC). We examine prognosis of patients with pathologic stage IIIA-N2 with classifying the number of positive N2 nodes into subgroups.
  
  
  METHODS
  From January 1997 to December 2004, 250 patients were diagnosed with pathologic stage IIIA-N2 disease. All patients underwent mediastinal lymph node dissection. After excluding 44 patients with preoperative chemotherapy, incomplete resection, and postsurgical mortality, 206 patients were included in the analysis. Patients were classified according to the number of positive N2 lymph nodes (N2a: 1 [n = 83], N2b: 2-4 [n = 82], N2c: ≥ 5 [n = 41]), and its correlation with survival outcomes were investigated.
  
  
  RESULTS
  With a median follow-up of 96.3 months, 5-year disease-free survival (DFS) was 27.2% (95% confidence interval [CI], 21.6-33.7), and 5-year overall survival (OS) was 37.7% (95% CI, 31.5-44.7) in all patients. The number of metastatic N2 lymph nodes was associated with DFS (P < .001) and OS (P = .01). In the N2a, N2b, and N2c groups, 5-year DFS rates were 38%, 24%, and 5%, respectively, and 5-year OS rates were 47%, 35%, and 24%, respectively. In a multivariate analysis, the number of metastatic N2 lymph nodes was an independent prognostic factor for DFS and OS.
  
  
  CONCLUSIONS
  Stratification of patients according to the number of metastatic N2 lymph nodes may improve the accuracy of prognostic prediction among patients with curatively resected stage IIIA-N2 NSCLC.
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Changhoon
authors.initials: C
authors.lastname: Yoo
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Shinkyo
authors.initials: S
authors.lastname: Yoon
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dae Ho
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seung-Il
authors.initials: SI
authors.lastname: Park
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dong Kwan
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Hyeong Ryul
authors.initials: HR
authors.lastname: Kim
authors.affiliation: Department of Thoracic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Se Hoon
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Pulmonology and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Kim
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea; Department of Pulmonology and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chang-Min
authors.initials: CM
authors.lastname: Choi
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Se Jin
authors.initials: SJ
authors.lastname: Jang
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Si Yeol
authors.initials: SY
authors.lastname: Song
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Su Ssan
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Choi
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae Cheol
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Cheolwon
authors.initials: C
authors.lastname: Suh
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jung-Shin
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Electronic address: swkim@amc.seoul.kr.
authors.forename: Sang-We
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Adjuvant treatment; N2; Non–small-cell lung cancer; Prognosis; Stage IIIA