A Cochrane review included 13 studies with a total of 2 290 subjects. There were no studies with an untreated control group. In a pooled analysis of three trials, overall survival was superior in patients with resectable stage I to IIIA non-small cell lung cancer (NSCLC) who underwent resection and complete mediastinal lymph node dissection compared with those undergoing resection and lymph node sampling (HR 0.63, 95% CI 0.51 to 0.78). A further trial found an increased rate of local recurrence in patients with stage I NSCLC treated with limited resection compared with lobectomy. One small trial found a survival advantage in favour of chemotherapy followed by surgery compared to chemotherapy followed by radiotherapy in patients with stage IIIA NSCLC. However none of the other trials in the review demonstrated a significant improvement in overall survival in patients treated with surgery compared with non surgical therapy.
Comment: The quality of evidence is downgraded by study quality (methodological weaknesses of some of the primary studies), and by imprecise results (limited study size for each comparison).