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.