Prognosis of non-small cell lung cancer patients with positive pleural lavage cytology after a thoracotomy: results of the survey conducted by the Japan Clinical Oncology Group

Objective: The purpose of this study was to clarify the prognosis of non-small cell lung cancer patients without pleural effusion whose intrapleural cancer cells were detected by a cytologic examination of pleural lavage fluid obtained immediately after a thoracotomy. Method: A questionnaire survey on the survival of the patients with positive pleural lavage cytology from January 1985 to December 1994 was performed by the Japan Clinical Oncology Group. Results: According to the data collected from 15 institutions, 1890 non-small cell lung cancer patients without pleural effusion underwent pleural lavage cytology immediately after thoracotomy and 142 (7.8%) of them were found to have intrapleural cancer cells detected by the cytological analysis. The information of survival on 113 patients was available. This comprised of 64 males and 49 females with a mean age of 64.6 years. The predominant histologic type was adenocarcinoma (74%). Out of these 113 patients, 109 (97%) underwent a surgical resection. The 5-year survival rate was 30% in all patients, 49% in pathological stage I ( n=35), 23% in stage II ( n=20) and 26% in stage IIIA ( n=34). Conclusion: Patients with a positive pleural lavage cytology in pathological stage I or II appear to have a poor 5-year survival rate.