title: Prognostic factors after pulmonary metastasectomy for colorectal cancer and rationale for determining surgical indications: a retrospective analysis.
abstract: OBJECTIVE
  We aimed to identify prognostic factors after pulmonary metastasectomy for colorectal cancer and propose the clinical application of them. Furthermore, we endeavored to provide a rationale for pulmonary metastasesectomy.
  
  
  BACKGROUND
  Several prognostic factors have been proposed, but clinical application of them remains unclear. Moreover, there is no theoretical evidence that pulmonary metastasectomy is indicated for colorectal cancer.
  
  
  METHODS
  We retrospectively analyzed 1030 patients who underwent pulmonary metastasectomy for colorectal cancer from 1990 to 2008. Prognostic factors were identified and the relationship of recurrent sites after pulmonary resection to pulmonary tumor size was assessed.
  
  
  RESULTS
  Overall 5-year survival was 53.5%. Median survival time was 69.5 months. Univariate analysis showed tumor number (P < 0.0001), tumor size (P < 0.0001), prethoracotomy serum carcinoembryonic antigen (CEA) level (P < 0.0001), lymph node involvement (P < 0.0001), and completeness of resection (P < 0.0001) to significantly influence survival. In multivariate analysis, all remained independent predictors of outcome. In patients whose recurrent sites extended downstream from the lung via hematogenous colorectal cancer spread, pulmonary tumor size was significantly larger than in those with recurrent sites confined to the lung and regions upstream from the lung.
  
  
  CONCLUSIONS
  We should utilize these prognostic factors to detect patients who might benefit from surgery. Therefore, we should periodically follow up advanced colorectal cancer patients by chest computed tomography to detect small pulmonary metastases before serum CEA elevation. Metastases to the lung or organs upstream from the lung are regarded as semi-local for colorectal cancer. This concept provides a rationale for validating surgical indications for pulmonary metastases from colorectal cancer.
authors.affiliation: Department of Thoracic Surgery, Kimitsu Central Hospital, Chiba, Japan. hptiida@hotmail.co.jp
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Iida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nomori
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Shiba
authors.forename: Jun
authors.initials: J
authors.lastname: Nakajima
authors.forename: Sakae
authors.initials: S
authors.lastname: Okumura
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Horio
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Matsuguma
authors.forename: Norihiko
authors.initials: N
authors.lastname: Ikeda
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshino
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Keigo
authors.initials: K
authors.lastname: Takagi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Goya
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kawamura
authors.forename: Chikuma
authors.initials: C
authors.lastname: Hamada
authors.forename: Koichi
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary* / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor