Bronchial resection margin length and clinical outcome in non-small cell lung cancer

Abstract

Complete surgical resection with pathologic negative margin is associated with the best prognosis in early-stage non-small-cell lung cancer (NSCLC). However, the impact of the length of the bronchial margin remains unknown. This study aimed to determine whether an increased bronchial resection margin length is correlated with an improved disease-free and overall survival rate. A total of 3936 consecutive pulmonary resections were performed between 25 June 1992 and 31 December 2007 at Mayo Clinic Rochester. A subset consisting of 496 patients with completely resected lesions (R0-resection), and a documented bronchial margin length was analyzed retrospectively. There were 340 men (68.5%) and 156 women (31.5%), with a mean age of 65.9±10.6 years. All patients underwent anatomic lobectomy or larger resection. Final pathology confirmed complete resection without microscopic residual tumor (R0-resection) in all patients. Mean length of the bronchial resection margin was 23.3±15.9mm. Overall, 190 patients (38.3%) suffered from disease recurrence with local recurrence in 35 patients, distant recurrence in 101, and both local and distant recurrence in 54 patients. Overall 5-year and 10-year local recurrence-free survival was 72.5% (95% confidence interval (CI): 67.3-78.1) and 68.0% (95% CI: 62.1-74.4), distant recurrence free survival 61.0% (95% CI: 55.8-66.6) and 52.9% (95% CI: 46.7-60.1) and overall survival 50.0% (95% CI: 45.1-55.3) and 28.8% (95% CI: 23.8-34.7). Tumor size and N-stage were associated with a worse prognosis in terms of local and distant recurrence, as well as survival (p<0.05). Histology was not significantly associated with local recurrence (p=0.28), though adenocarcinoma relative to squamous cell carcinoma was associated with an increased risk of distant recurrence (p<0.01). There was no significant association between type of surgical resection and local (p=0.37) or distant recurrence (p=0.37). Neither local (p=0.56) or distant recurrence (p=0.46), nor survival (p=0.54) was associated with the bronchial margin length. In multivariate models including age, N-stage, and gender there were no significant overall associations of margin length (≤5, 6-10, 11-15, 16-20, >20mm) and local recurrence (p=0.51), distant recurrence (p=0.33), or survival (p=0.75). When complete surgical resection is achieved, the extent of the bronchial margin has no clinically relevant impact on disease-free and overall survival in NSCLC.