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

Abstract

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. 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. 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%). 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.