title: Therapeutic value of lymph node dissection for right middle lobe non-small-cell lung cancer.
abstract: BACKGROUND
  Superior mediastinal and #11i lymph node (LN) metastases are adverse prognostic factors in patients with middle lobe lung cancer. We aimed to clarify the benefit of thorough lymphadenectomy by LN station or zone in middle lobe non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  Among 295 patients who underwent pulmonary resection and thorough lymphadenectomy for primary right middle lobe (RML) NSCLC at two institutions, we enrolled 68 patients (33 men, 35 women) and retrospectively studied their data. We divided each N1 location (i.e., #10, #11s and #11i) into N1(-)N2(+) and N1(+)N2(+) and divided the #12m location into N1(+)N2(-), N1(-)N2(+) and N1(+)N2(+).
  
  
  RESULTS
  Interlobar node involvement was rare in pN1 NSCLC when compared with that in other N1 nodes. Lymph node dissection (LND) was beneficial when the hilar zone (HZ)/interlobar zone (IZ) LNs were located at the intermediate point of the upper zones (UZs) and subcarinal zones (SCZs), with the therapeutic benefit at the SCZ being 2.8-fold higher than that at the UZ and 9.7-fold higher than that at the lower zone (LZ). Furthermore, LND evidently had greater therapeutic value for the SCZ than the UZ, which was compatible with skip N2 metastases.
  
  
  CONCLUSIONS
  For middle lobe NSCLC, mediastinal LND should be considered a priority in the SCZ than in the UZ. Moreover, the HZ/IZ is central to unfavourable prognoses in patients with pN2 middle lobe NSCLC.
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kuroda
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Sakao
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Mingyon
authors.initials: M
authors.lastname: Mun
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Motoi
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.affiliation: 1 Department of Thoracic Surgery, Aichi Cancer Center Hospital, Chikusa-ku, Nagoya 464-8681, Japan ; 2 Department of Thoracic Surgical Oncology, 3 Department of Pathology, Japanese Foundation for Cancer Research, Cancer Institute Hospital, Kotouku, Tokyo 135-8550, Japan ; 4 Department of Pathology and Molecular Diagnosis, Aichi Cancer Hospital, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Sakae
authors.initials: S
authors.lastname: Okumura
keywords: Lymph node dissection (LND); lung cancer; non-small-cell lung cancer (NSCLC); right middle lobe (RML); therapeutic index (TI)