Impact of Positive Pleural Lavage Cytology for Each Stage of Non-Small Cell Lung Cancer Patients.

Background: Positive preresection pleural lavage cytology (PLC) is a poor prognostic factor in non-small cell lung cancer (NSCLC). This study evaluated the prognostic value of PLC for the different pathologic stages (p-stages) of NSCLC.

Methods: A retrospective analysis was conducted of all 1293 staged patients who underwent curative resection in the Shizuoka Cancer Center Hospital, Shizuoka, Japan, for NSCLC to evaluate the impact of PLC on survival, specifically in patients with p-stage I NSCLC. The survival rate between patients with and without PLC was compared using the Kaplan-Meier method with the log-rank test for comparison.

Results: PLC was identified in 50 of the 1293 patients (3.9%) and was correlated with lymph node metastasis (P < .001), a pathologic tumor size larger than 3 cm (P = .033), the presence of pleural invasion (P < .001), and adenocarcinoma (P = .038). In patients with PLC, the 5-year disease-free survival (DFS) was 31.1%, compared with 75.7% for patients with a negative PLC (PLC) (P < .001). On multivariate analysis, the PLC status was an independent prognostic factor of DFS (hazard ratio 1.70; P = .013). Among the 818 patients with p-stage I NSCLC, PLC was identified in 22, with a 5-year DFS of 40.4%. The prognosis in patients with p-stage I NSCLC with PLC was equal to that in patients with p-stage IIIA NSCLC with PLC (5-year DFS, 40.4% and 39.0%).

Conclusions: PLC is an independent prognostic factor in early-stage NSCLC. Therefore, it may be appropriate to up-stage an NSCLC diagnosis in the presence of PLC, especially for patients with p stage I.