title: Prognosis and segment-specific nodal spread of primary lung cancer in the right lower lobe.
abstract: BACKGROUND
  Although lobe-specific nodal spread of primary lung cancer has been recently described, segment-specific nodal spread remains unclear. We investigated the frequency of hailer and mediastinal lymph node involvement and survival in patients with tumors located in the superior segment (SS) and basal segment (BS) in the right lower lobe.
  
  
  METHODS
  Two hundred and sixty-three patients with primary lung cancer originating in the right lower lobe underwent lobectomy with systematic mediastinal lymph node dissection. Patients were categorized into two groups: SS (n = 114) or BS (n = 149).
  
  
  RESULTS
  Frequencies of metastasis to station 11s and 11i were significantly higher in the SS (P < 0.0001) and BS groups (P = 0.022), respectively. Both the SS and BS groups showed a high frequency of subcarinal mediastinal zone (station 7) metastasis (96.9% and 90.6%, respectively; P = 0.271). The frequencies of superior mediastinal zone (station 2R and 4R) metastasis were 37.5% in the SS and 35.8% in the BS group (P = 0.878). In patients with pN2 disease, three-year disease-free survival was significantly shorter in the SS (22.6%) than the BS group (42.1%; P = 0.020). In the BS group, the independent predictive factors of a poor or good prognosis were metastasis to station 11i or skip metastasis, respectively; however, we did not detect an independent prognostic factor in the SS group. In the right lower lung lobe, there was no segment-specific nodal spread.
  
  
  CONCLUSIONS
  When segmentectomy is undertaken, mediastinal lymph node dissection should be performed in proportion to lobectomy.
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan ; Department of Thoracic Surgery, Aichi Cancer Center Hospital Nagoya, Japan ; Department of General Surgical Science, Graduate School of Medicine, Gunma University Maebashi, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tomizawa
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Suda
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takemoto
authors.affiliation: Department of Thoracic Surgery, Aichi Cancer Center Hospital Nagoya, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizuno
authors.affiliation: Department of Thoracic Surgery, Aichi Cancer Center Hospital Nagoya, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kuroda
authors.affiliation: Department of Thoracic Surgery, Aichi Cancer Center Hospital Nagoya, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Sakakura
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakaguchi
authors.affiliation: Department of General Surgical Science, Graduate School of Medicine, Gunma University Maebashi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kuwano
authors.affiliation: Department of Surgery, Division of Thoracic Surgery, Kinki University Faculty of Medicine Osaka-sayama, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mitsudomi
authors.affiliation: Department of Thoracic Surgery, Aichi Cancer Center Hospital Nagoya, Japan.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Sakao
keywords: Basal segment; primary lung cancer; prognosis; segment-specific nodal spread; superior segment