Introduction The value of pleural lavage cytology (PLC) in assessing the prognosis of early stage lung cancer is still controversial. No systematic review has investigated the relationship between PLC and lung cancer recurrence. Our primary goal was to investigate the association between positive pre-resection PLC and pleural, distant and overall tumour recurrence in patients undergoing surgical resection.

Methods Medline, EMBASE and Google Scholar databases were searched up to 2011. All studies reporting relevant outcomes in both patient groups were included. Data were extracted for the following outcomes of interest: overall, local and distant recurrence; and freedom from death (survival—overall and patients with stage I disease only). Random effects meta-analysis was used to aggregate the data. Sensitivity and heterogeneity analysis were performed.

Results A meta-analysis of eight studies at maximum follow-up demonstrated a significant association between positive pre-resection PLC and increased risk of post-resection overall recurrence (OR 4.82, 95% CI 2.45 to 9.51), pleural recurrence (OR 9.89, 95% CI 5.95 to 16.44) and distant cancer recurrence (OR 3.18, 95% CI 1.57 to 6.46). Furthermore, a meta-analysis of 17 studies suggested that positive pre-resection PLC was also associated with unfavourable survival (HR 2.08, 95% CI 1.71 to 2.52). These findings were supported by sensitivity analysis.

Discussion Positive pre-resection PLC is associated with higher overall, distant and local tumour recurrence and unfavourable patient survival outcomes. This technique may therefore act as a predictor of tumour recurrence and adverse survival. Furthermore, its role in including adjuvant chemotherapy to the management protocol should be investigated within randomised controlled trials.