title: Outcome following surgery for primary lung cancer with interlobar pleural invasion.
abstract: OBJECTIVE
  To determine whether interlobar pleural invasion into the adjacent lobe (interlobar P3) should be assessed as T3 according to the tumor-node metastasis classification.
  
  
  METHODS
  Surgically treated patients with primary lung cancer (n = 322) were analyzed.
  
  
  RESULTS
  Tumors with interlobar P3 had a significantly lower incidence of mass screening detection, a higher occurrence rate of squamous cell carcinoma, and a larger tumor diameter than tumors without interlobar P3. The lymph node metastatic rate did not differ between the patients with and without interlobar P3. The 5-year survival rate of patients with interlobar P3 was 63% and the rates of other patients were 56% with T1 disease, 57% with T2, 31% with T3, and 19% with T4. The survival rate for patients with interlobar P3 was higher than for those with T3 without interlobar P3 (P < 0.05). The 5-year survival rate of the patients with interlobar P3 was lower in adenocarcinoma (39%) than in squamous cell carcinoma (69%, P < 0.01). The results were similar when the analysis was restricted to patients without lymph node metastasis. In adenocarcinoma, the survival rate for interlobar P3 was between the rates for T2 (53%) and T3 (13%) without interlobar P3, whereas in squamous cell carcinoma, the survival rate for interlobar P3 was between the rates for T1 (88%) and T2 (54%) without interlobar P3.
  
  
  CONCLUSIONS
  Tumors with interlobar P3 should be classified as T2 only in squamous cell carcinoma.
authors.affiliation: First Department of Surgery, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nonaka
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kataoka
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Naoya
authors.initials: N
authors.lastname: Horichi
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Ohgiya
authors.forename: Miki
authors.initials: M
authors.lastname: Kushima
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kunimura
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Takaba
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009367:Neoplasm Staging; D016066:Pleural Effusion, Malignant / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D011013:Pneumonectomy / Q000379:methods; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D016896:Treatment Outcome