Prognostic significance and possibility in guiding adjuvant therapy of the pleural lavage cytology in patients with non-small cell lung cancer.

Pleural lavage cytology (PLC) has been reported to be a significant prognostic factor in patients with operable non-small cell lung cancer (NSCLC). PLC may detect micro metastasis in patients without apparent pleural effusion or dissemination. Although many studies have reported PLC as a good predictor of postoperative recurrence, its role in the staging of NSCLC and in determining adjuvant therapy is still controversial. From June 1999 through December 2006, PLC immediately after thoracotomy was performed in 284 NSCLC patients without effusion or dissemination. Cases with exploratory thoracotomy were excluded from this study. Results of PLC were evaluated with other clinicopathological factors, and the difference in survival according to PLC status was investigated. Thirteen patients with positive PLC showed a poorer disease-free survival (P<0.0001) compared to those with negative PLC. The difference in survival rate between patients with positive and negative PLC, was significant in stage I disease, but not in stage II and III disease. PLC is a useful predictive marker for postoperative recurrence and should be routinely evaluated in lung cancer surgery, especially, in stage I disease. PLC might also assist in guiding adjuvant therapy.