Re-Assessment of Intentional Extended Segmentectomy for Clinical T1aN0 Non-Small Cell Lung Cancer

Abstract

This study compares long-term prognosis of intentional extended segmentectomy and lobectomy ofclinical T1aN0M0 non-small cell lung cancer (NSCLC). Risk factors of local-regional recurrence are identified and segmentectomy outcomes are examined per segment. 164 intentional extended segmentectomies were compared with 73 lobectomies subcategorized by consolidation to maximum tumor diameter ratio (C/T) measured by computed tomographies. Preoperative characteristics were propensity score matched to evaluate local-regional recurrence-free survival using the log-rank test. Preoperative factors and surgical procedure were analyzed with the Cox proportional hazards regression model to identify independent predictor of local-regional recurrence. Local-regional recurrence per segment were assessed by Kaplan-Meier estimates between both groups. No recurrences were observed for 46 C/T ≤0.5 segmentectomies. In 59 C/T >0.5 propensity score-matched pairs, 5-year local-regional recurrence-free survival rates of segmentectomies were 76.3%, versus 91.5% for lobectomies (p= 0.082). Multivariate analysis confirmed segmentectomies to be the only independent risk factor for local-regional recurrence-free probability (p= 0.020). Subset analysis reveals superior segmentectomies have significantly less local-regional recurrence (p= 0.029) than other segments and comparable prognosis to lower lobectomies. Left upper lobe segmentectomies also showed comparable prognosis to lobectomies. Segmentectomies in the right upper lobe and of basal segments showed significantly higher local recurrence (p= 0.001) than other segments. Basal segmentectomies showed significantly poor prognosis versus lower lobectomies (p= 0.005). For radiographically invasive right upper lobe or basal segment clinical T1a NSCLC, strict inclusion criteria is necessary for intentional segmentectomy. For superior and left upper lobe segments, however, segmentectomies may be preferred with prognosis comparable to lobectomies.