Efficacy of adjuvant chemotherapy for lung adenocarcinoma patients with positive pleural lavage cytology findings.

OBJECTIVES Positive pleural lavage cytology (PLC) findings are considered to be predictive of a poor prognosis in patients with non-small-cell lung cancer (NSCLC). We investigated the clinical benefit of adjuvant chemotherapy for lung adenocarcinoma patients with positive PLC findings. METHODS We retrospectively reviewed the medical records of lung adenocarcinoma patients who underwent tumour resection and had positive PLC findings between January 2000 and December 2009. RESULTS Fifty-three patients (4.8%) of 1114 patients with lung adenocarcinoma had positive PLC findings. The median follow-up period was 33.6 months. Adjuvant chemotherapy was administered to 24 patients (adjuvant chemotherapy group); 7, 8 and 9 patients had pathological Stage I, II and III, respectively . The surgery-alone group comprised 29 patients; 12, 8 and 9 patients had pathological Stage I, II and III, respectively. The 5-year recurrence-free survival (RFS) rates were 34.6 and 15.7% (P < 0.01) in adjuvant chemotherapy and surgery-alone groups, respectively. The rate of distant recurrence was significantly reduced in the adjuvant chemotherapy group (25.0 and 58.6%; P = 0.01). Even for Stage I cases, adjuvant chemotherapy tended to improve the 5-year RFS rate compared with surgery alone (60.1 and 29%; P = 0.11). Multivariate analysis for RFS revealed that adjuvant chemotherapy [hazard ratio (HR), 0.45; P = 0.03], tumour size >30 mm (HR, 2.23; P = 0.02) and lymph node metastasis (HR, 2.67; P < 0.01) were significant independent prognostic factors for recurrence. CONCLUSIONS Adjuvant chemotherapy for lung adenocarcinoma patients with positive PLC findings significantly improved recurrence-free survival.