Background: Cytologic approaches such as pleural lavage cytology (PLC) are considered as possible aids to assessing prognosis of lung cancers. However, there is some controversy whether radical surgery is warranted based on the positive PLC findings with stage I non-small cell lung cancers (NSCLCs).
Methods: From January 1991 to December 2002, PLC was performed before any manipulation or resection of the lung for 853 consecutive patients who had no macroscopic pleural effusion, dissemination, or diffuse adhesions and who subsequently underwent curative resection for NSCLCs. Results of PLC with reference to clinicopathologic characteristics, adjuvant therapy, 5-year survival, and recurrence patterns were analyzed.
Results: PLC findings were positive in 41 patients (4.8%), rates being most frequent with adenosquamous carcinomas and adenocarcinomas. In the positive group, distant metastases (72%) and pleural recurrence (25%) (p = 0.0011) were often observed, and the survival rate was significantly poorer (p < 0.002), even for patients with stage I disease (p = 0.009). As adjuvant therapies in the positive group after resection, 6 patients received hypotonic cisplatin and 15 received a distilled water infusion into the pleural space. Although only 2 patients had pleural recurrence, these therapies did not improve long-term outcome.
Conclusions: PLC is a distinct prognostic factor for early stage lung carcinomas. Thus, we suggest that cytologic examination of PLC should be routine, even for patients with stage I NSCLCs before beginning lung resection. Moreover, curative resection, followed by adjuvant systemic therapy, could be necessary for improvement of outcome.