Video-assisted mediastinoscopic lymphadenectomy (VAMLA): mature results for staging non-small cell lung cancer with normal mediastinum.

OBJECTIVES: The aim of this study is to analyze the accuracy of video-assisted mediastinoscopic lymphadenectomy (VAMLA) and the unsuspected (u) N2-3 rates in patients with non-small cell lung cancer (NSCLC) and normal mediastinum by integrated positron emission tomography (PET) - computed tomography (CT).

METHODS: Prospective observational single-center study of 603 consecutive VAMLAs from 2010 to 2022.

EXCLUSION CRITERIA: other indications (n=32); tumors different from NSCLC (n=91); cN2-3 tumors by PET-CT (n=46). Systematic nodal dissection was the gold standard to validate negative VAMLAs. Those patients with negative VAMLA and missing reference standard test were excluded. uN2-3 rates were analyzed in the global series and in the subgroups of tumors according to their clinical nodal and tumor categories. Pathologic findings were reviewed, and staging values were calculated.

RESULTS: 383 patients with clinical (c) N0-1 NSCLC underwent VAMLA. Staging values of VAMLA were: sensitivity, 0.98 (95% CI: 0.92- 0.99); negative predictive value, 0.99 (95% CI: 0.98-1); and diagnostic accuracy, 0.99 (95% CI: 0.98-1). The uN2-3 rate for the whole series (n=383) was 18.8%. The uN2-3 rates according to presurgical nodal and tumor categories determined by PET-CT were: 3.6% (4/111) in cT1N0; 16.3% (18/110) in cT2N0; 10,25% (4/39) in cT3N0; 32% (7/22) in cT4N0. 42% (39/93) in cN1; Complication rate: 7%.

CONCLUSIONS: This series of NSCLC with normal mediastinum staged by VAMLA demonstrates a high accuracy of this technique and a high rate of uN2-3 disease (specially in cN1 and cT4N0). VAMLA could be considered the reference staging procedure for staging cN0-1 NSCLC.