Intraoperative Pleural Lavage: Is It a Valid Prognostic Factor in Lung Cancer?

In patients undergoing lung resection for non-small cell lung cancer (NSCLC), the primary TNM (tumor–regional lymph node–distant metastasis) staging system is the best prognostic factor. However, it is necessary to investigate other factors that could more accurately predict a patient's prognosis. In this study we evaluated the significance of positive intraoperative pre-resectional lavage in patients with NSCLC. We enrolled 84 patients (79 men, 5 women) aged between 36 and 81 years (mean age, 64.8 years) undergoing a major lung resection for NSCLC, with no preoperative evidence of pleural effusions. Intraoperatively, the patients were given a pre-resectional pleural lavage with physiologic saline solution. The fluid was aspirated and sent to cytology. Pre-resectional pleural lavage was positive in 19 patients (22.6%). The lavage was positive in 7.3% in patients with early stage I disease (3/41) and 37.2% in patients with stage II/III disease. In the group of 16 patients with chest wall neoplastic involvement (T3), 9 had a positive lavage (56.2%; p = 0.05). No significant correlation was found between positive lavage and nodal status, visceral pleural involvement, or histologic findings. Patients with malignant cells in the pre-resectional lavage had a significantly shorter survival than patients with a negative lavage ( p = 0.025). A positive cytology finding of intraoperative pre-resectional pleural lavage could be an important prognostic factor in patients undergoing major lung resection for NSCLC. Patients with a positive lavage should be upstaged. However, larger series are needed to define accurately the role of this technique in early stage lung cancer.