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†.

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).