Clinical outcomes of microscopic residual disease after bronchial sleeve resection for non–small cell lung cancer

Objectives: To evaluate the significance of microscopic residual disease (MRD) at the bronchial resection margin after bronchial sleeve resection in non–small cell lung cancer. Methods: We retrospectively reviewed 536 consecutive patients who underwent bronchial sleeve resection between 1995 and 2015. Clinical outcomes, including recurrence and long-term survival, were analyzed according to the bronchial resection margin status (R0 = complete resection and R1 = microscopic residual tumor). Results: Forty patients (7.5%) were identified to have MRD. During a 52.4-month follow-up (range, 0.1-261.0 months), there was no significant difference in 5-year overall survival (61.8% vs 61.5%; P = .550) and 5-year recurrence-free survival (53.7% vs 59.0%; P = .390) between groups R1 and R0. Multivariable cox regression analysis demonstrated that the margin status (group R1) was not associated with significantly decreased overall survival and recurrence-free survival. In group R1, 3 patients (7.5%) showed locoregional recurrence, including 1 patient (2.5%) with anastomotic recurrence. There were no significant differences between both groups in anastomotic recurrence (2.5% vs 2.6%; P = 1.000), locoregional recurrence (7.5% vs 12.7%; P = .476), and distant recurrence (25.0% vs 23.2%; P = .947) rates. Subgroup analysis of group R1 revealed a significant trend toward an increasing recurrence rate as the pathological extent of MRD advanced toward invasive extramucosal carcinoma (P for trend = .015). Conclusions: In our experience of bronchial sleeve resection, the oncologic outcome of MRD was not jeopardized. Furthermore, the pathological extent of MRD might be helpful for recurrence prediction and treatment planning.