Locoregional recurrence after segmentectomy for clinical-T1aN0M0 radiologically solid non-small-cell lung carcinoma

We aimed to identify the clinicopathological features of loco-regional recurrence after segmentectomy for clinical-T1aN0M0 radiologically invasive non-small-cell lung carcinoma (NSCLC).

Between 2008 and 2014, 353 patients underwent pulmonary lobectomy or segmentectomy with nodal dissection for clinical-T1aN0M0 radiologically invasive NSCLC showing 0.5 ≤ consolidation tumour ratio (CTR)≤1.0 on thin-section computed tomography (CT). Radiological invasive NSCLC was divided into two groups, i.e. part-solid (0.5 ≤ CTR < 1.0) and pure-solid (CTR = 1.0). Significant prognostic factors for oncological outcomes were evaluated by multivariate analysis.

Lobectomy was performed in 270 (76.5%) patients and segmentectomy in 83 (23.5%). Locoregional recurrence-free survival (LRFS) of clinical-T1a radiologically invasive NSCLC on the whole showed no significant differences between the lobectomy and segmentectomy arms (3-year LRFS, 93.0 vs 90.1%, P  = 0.2725). In contrast, the multivariate analysis revealed that radiologically pure-solid appearance and tumour size were significant predictors of loco-regional recurrence ( P  = 0.0106, 0.0408). Among 212 clinical-T1a radiologically pure-solid NSCLCs, frequency of loco-regional recurrence was high in the segmentectomy arm (20.7%) compared with that of lobectomy arm (8.2%). Furthermore, segmentectomy and larger tumour size were independent significant clinical factors of loco-regional recurrence based on the multivariate analysis ( P  = 0.0292, 0.0402). The 3-year LRFS of the segmentectomy arm was significantly worse than that of the lobectomy arm in the c-T1a disease (82.2 vs 90.6%, P  = 0.0488) provided the tumour showed a pure-solid appearance.

Even in cases of small-sized lung carcinoma, segmentectomy should be applied with great caution especially for a radiological pure-solid NSCLC on thin-section CT due to their high incidence of loco-regional recurrence.