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.