The Impact of Pleural Lavage Cytology Before and After Resection on Prognosis

Aim: Regardless of pleural effusion, presence of tumor in pleural cavity indicates presence of more aggressive tumor. In this study, we analysed positive tumor results in preoperative pleural lavage in operable malignant cases with no pleural fluid according to the mass and mediastinal lymph node characteristics. Material and Method: Pleural lavage before preoperative dissection and after resection was performed on 199 cases that underwent surgery for non small cell lung cancer (NSCLC). Findings of lavage were statistically evaluated based on gender, lesion shape and size, lymph node involvement in positron emission tomography- computed tomography (PET-CT), SUV-max value of lesion, localisation of the lesion, N1 and N2 metastases, local invasion findings, histopathological type of tumor and type of resection. Results: Cases included in this study were followed for four years. Ten of the cases (5%) had tumor recurrence and 12 of them (6%) had distant organ metastasis. In multivariable analysis, significant correlation was found between the first positive pleural lavage cytology and postoperative distant organ metastasis; the last pleural lavage cytology and tumor recurrence; postoperative distant organ metastasis and lymph node metastasis and the first positive lavage cytology; tumor recurrence and PET-CT lymph node uptake, lymph node metastasis and the last positive pleural lavage cytology. Discussion: Recently there has been an increase in studies on pleural lavage analysis and there is a need for standardization in lavage timing and sampling. We hope that positive lavage cytology, like malign effusion, will be accepted as a prognostic factor in staging as more studies based on wider series are conducted