Quality comparison of mediastinal lymph node dissection between video-assisted thoracic surgery and open thoracotomy: a supplementary analysis of the phase 3 Japan Clinical Oncology Group 1413 trial†

Abstract

Objectives: This study aimed to compare the quality of mediastinal lymph node dissection (LND) during lobectomy for clinical stage I-II non-small cell lung cancer (NSCLC) between video-assisted thoracic surgery (VATS) and open thoracotomy, using data from the Japan Clinical Oncology Group (JCOG) 1413 phase 3, randomized, controlled trial.

Methods: This analysis draws information from JCOG1413, comparing the efficacy of lobe-specific versus systematic LND with standardized LND protocols. A total of 1685 patients were included in this exploratory analysis (1251 VATSs and 434 open thoracotomies). Propensity score matching (PSM) ensured a balanced distribution of patient characteristics. The study's end-point was N2 upstaging, defined as the proportion of upstaging from clinical N0-N1 to pathological N2.

Results: Among 1685 patients, 141 (8.3%) and 118 (7.0%) had pathological N1 and N2, respectively. The PSM yielded 852 patients (426 per group). The N2 upstaging proportions (7.8% [VATS] vs 7.3% [open], P = 0.795) and the influence of the lobectomy type on N2 upstaging were not significantly different between the 2 groups. The median number of N2 lymph nodes dissected per defined LND extent was similar (systematic: 13 in both groups, P = 0.236; lobe-specific: 7 in both groups, P = 0.720). Additionally, no significant difference in N2 upstaging was observed between hybrid and complete VATS groups (6.7% in both groups, P =. 982).

Conclusions: This study found no significant differences in N2 upstaging proportions between the VATS and open thoracotomy groups of patients with clinical stage I-II NSCLC. This suggests comparable quality of mediastinal LND in both surgical approaches.

Clinical trial registration: This study is a sub-analysis of the JCOG1413 randomized controlled trial. The JCOG1413 trial is registered with the UMIN Clinical Trials Registry (UMIN0000025530).

Keywords: Lymph node dissection; Non-small cell lung cancer; Surgical approach.