RESUMEN
A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'In lung cancer patients with unexpected pleural metastasis detected during operation, is surgical resection of primary tumour superior to exploratory thoracotomy without resection in improving long-term survival?'. Altogether, 1443 papers were found using the reported search, of which 1 meta-analysis and 10 retrospective observational cohort studies represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. One meta-analysis and 9 cohort studies found that surgical resection of the primary tumour, on the discovery of pleural metastases, yielded a better overall survival than exploratory thoracotomy alone, while 1 cohort study showed no difference. Six studies found that main tumour resection was an independent favourable prognostic factor for overall survival in lung cancer patients with unexpected pleural metastasis detected during operation, while 3 cohort studies also showed improved progression-free survival over exploratory thoracotomy. Therefore, we conclude that surgical resection of the primary tumour is superior to exploratory thoracotomy in treating lung cancer patients with unexpected pleural metastasis detected during operation.