The impact on survival of positive intraoperative pleural lavage cytology in patients with non-small-cell lung cancer

Objective: The aim of this study was to analyze intraoperative pleural lavage cytology results in patients with non-small-cell lung cancer and quantify the impact on survival and recurrence. Methods: From August 1992 through November 2006, pleural lavage cytology results before and after lung resection were both available in 2178 patients with non-small-cell lung cancer. We assessed the pre-pleural lavage cytology impact on survival, comparing with 9 factors available before lung resection by multivariate analyses. We also compared the impact with that of pleural dissemination or malignant pleural effusion. For post-pleural lavage cytology, we analyzed its survival impact in relation with 15 clinicopathologic factors, including those available after resection, by multivariate analyses. Results: Pre-pleural lavage cytology proved to be a strong independent prognostic factor, but the 5-year survival rate was 37% in 65 patients without dissemination but with a positive pre-pleural lavage cytology, which was significantly higher than 12% in 86 patients with dissemination. When factors available after resection were combined, post-pleural lavage cytology showed a stronger survival impact than pre-pleural lavage cytology. Post-pleural lavage cytology was also a strong predictor of recurrence. The positive post-pleural lavage cytology group had a marginally, but not significantly, better survival compared with the malignant pleural effusion group. Almost all patients with positive post-pleural lavage cytology relapsed within 5 years. Conclusions: Pre-pleural lavage cytology is of less use in clinical practice. Post-pleural lavage cytology was a very strong independent prognostic factor, and almost all patients with positive post-pleural lavage cytology relapsed within 5 years. We propose that positive post-pleural lavage cytology disease should be classified to pathologic T4 and managed similarly to dissemination. (J Thorac Cardiovasc Surg 2010; 139: 1246-52)