title: Intraoperative pleural lavage cytology after lung resection as an independent prognostic factor for staging lung cancer.
abstract: OBJECTIVE
  Although malignant pleural effusion or dissemination is regarded as T4 per TNM classification of lung cancer, the prognostic significance in staging of pleural lavage cytologic examination remains undetermined. The purpose of this study was to clarify the utility of pleural lavage cytologic staging as a prognostic factor in patients with non-small cell lung cancer.
  
  
  METHODS
  In 1271 patients with lung cancer who underwent curative resection, intraoperative pleural lavage cytologic examination was performed at thoracotomy (first cytologic examination), immediately after pulmonary resection and mediastinal lymph node dissection (second cytologic examination), and after last washing of pleural cavity (third cytologic examination). Positive first cytologic result represented cytologic positive result before lung resection; positive second and third cytologic results were regarded as cytologic positive results after lung resection.
  
  
  RESULTS
  Eighty-nine patients (7.0%) had positive findings of pleural lavage cytologic examination before or after lung resection. Five-year survivals were 44.1% for patients with positive results before lung resection and 23.4% for patients with positive results after lung resection, both significantly worse than that for patients with negative results. Multivariate analyses revealed that positive lavage result after lung resection was an independent prognostic factor. We found significantly greater pleural recurrence among patients with positive pleural lavage cytologic results after lung resection than among those with negative results.
  
  
  CONCLUSIONS
  In addition to TNM classification, results of pleural lavage cytologic examination after lung resection should be considered when staging non-small cell lung cancer. Adjuvant systemic therapy may improve outcome for patients with positive results.
authors.affiliation: Department of Thoracic Surgery, Osaka Prefectural Hospital Organization, Osaka Prefectural Medical Center for Respiratory and Allergic Disease, Osaka, Japan. yasushishintani@aol.com
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shintani
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Ohta
authors.forename: Teruo
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Ikeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanou
authors.forename: Emiko
authors.initials: E
authors.lastname: Tomita
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yasumitsu
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ohno