title: Survival impact of node zone classification in resected pathological N2 non-small cell lung cancer.
abstract: We assessed the prognostic value of the 'Zone-classification' which has been proposed by the Japanese Association for Lung Cancer (JALC) for mediastinal nodal metastases in non-small cell lung cancer (NSCLC). Among 357 NSCLC patients who underwent curative surgery, 46 patients with pathological (p) N2 disease were divided into two groups as follows: 32 patients in whom the nearer zone was involved were classified as the pN2a-1 group, and 14 patients in whom the further mediastinal node station was involved were classified as the pN2a-2 group. The proportions of patients with non-adenocarcinoma histology, with multiple station metastases with the involvement of four or more nodes, and who underwent pneumonectomy, were higher in the pN2a-2 group. The 'Zone-classification' proved to be a significant prognostic factor in a univariate analysis (the 5-year overall survival rate, 7.1% for pN2a-2 versus 21.9% for pN2a-1; P < 0.01). A multivariate analysis confirmed that pN2a-2 sub-classification (hazard ratio 2.77; P = 0.03) and undergoing pneumonectomy (hazard ratio 4.86; P < 0.01) were independent and significant factors in predicting a poor prognosis. In pN2 NSCLC patients, the involved mediastinal zone according to the primary tumour site was important in prediction of survival.
authors.affiliation: Department of Surgery II, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. t-baba@med.uoeh-u.ac.jp
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Baba
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Uramoto
authors.forename: Taiji
authors.initials: T
authors.lastname: Kuwata
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Chikaishi
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: So
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hanagiri
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging / Q000379:methods*; D011013:Pneumonectomy / Q000009:adverse effects / Q000401:mortality; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome