Pleural lavage cytology after lung resection in patients with non-small cell lung cancer and the feasibility of 20 mL saline solution

Abstract

Background: There are two issues to be discussed in pleural lavage cytology (PLC) for resected non-small cell lung cancer (NSCLC) whether it should be performed before (pre-PLC) or after (post-PLC) the lung resection and the dose of saline varies widely among the institutions.

Methods: We retrospectively reviewed the clinical records of 466 consecutive patients who underwent a curative resection for NSCLC and received both a pre- and post- PLC using 20 mL of saline from January 2001 to December 2011.

Results: There were 24/28 of positive pre- and post-PLC and 442/438 negative pre- and post-PLCs, respectively. Patients with a positive pre- or post-PLCs had significantly worse 5-year survival rates than those with negative results (pre-PLC positive/negative; 32.6%/69.9%, p = 0.001, post-PLC positive/negative; 21.4%/71.1%, p < 0.001, respectively). The post-PLC (p = 0.01) was an independent prognostic factor for the overall survival by a multivariate analysis, whereas the pre-PLC was not (p = 0.79).

Conclusions: The post-PLC was a more significant prognostic factor than the pre-PLC. Further, 20 mL of saline seemed feasible because of the consistent results compared to the past reports using a greater dose of saline for regarding the positive rates of the PLC and its prognostic significance.

Keywords: Lung cancer staging; Lung cancer surgery; Pleural lavage cytology; Prognostic factor.