Pleural lavage cytology immediately after thoracotomy and before closure of the thoracic cavity for lung cancer without pleural effusion and dissemination: Clinicopathologic and prognostic analysis

Background: The significance of intraoperative pleural lavage cytology (PLC) in lung cancer patients without malignant effusion remains undetermined in terms of staging, prognosis, and local management. Methods: PLC was performed both after thoracotomy and before closure of the thoracic cavity in 325 patients with lung cancer without malignant pleurisy. Results: According to the PLC results (positive [+] or negative [-] after thoracotomy/before closure), the patients were classified as follows: group A (-/-), 262 patients; group B (+/-), 19; group C (-/+), 22; and group D (+/+), 22. In comparison with group A, group C showed more advanced stage with aggressive nodal involvement, and group D showed more advanced lung cancer related to pleural and nodal involvement, whereas group B showed characteristics similar to those of group A. The rate of pleural recurrence in group D was the highest (26%). In particular, pleural recurrence was seen in the patients with a relatively large number of adenocarcinoma cells in PLC after thoracotomy. The patients in groups C and D, especially those with adenocarcinoma, showed poorer prognosis, but in a multivariate analysis, PLC status was not an independent prognostic factor. Conclusions: PLC status after thoracotomy provides useful information in the detection of high-risk subgroup for pleural recurrence. Although PLC status is closely associated with survival, its prognostic value is not independent.