Is surgical lymph node assessment justified for ground glass opacity-dominant lung adenocarcinoma?

INTRODUCTION: The necessity of lymph node dissection (LND) as part of curative-intent surgery for ground-glass opacity (GGO)-dominant lung adenocarcinoma has been called into question, given the favorable prognosis and indolent behavior of these tumors. However, the oncological safety of omitting LND in cases of GGO-dominant lung adenocarcinoma remains controversial, and current guidelines continue to recommend it. METHODS: This study was designed as a retrospective, single-center cohort study. Patients with cT1N0M0 lung adenocarcinoma who underwent surgical resection between 2010 and 2023 were categorized as GGO-dominant or solid-dominant cohorts based on consolidation-to-tumor ratios in preoperative computed tomography scans. The primary endpoint was the incidence of occult lymph node (LN) metastasis. RESULTS: A total of 726 consecutive patients were included in this study, categorized as GGO-dominant in 50 patients and solid-dominant in 676 patients. GGO-dominant tumors were more frequently observed in female patients (p = 0.03), whereas no significant differences were found between the groups with respect to age, smoking status, or ECOG performance status. GGO-dominant morphology was associated with lower pT stage and lower rates of pleural and lymphovascular invasion. The incidence of occult LN metastasis was 4% (n=2) in the GGO-dominant cohort and 11.8% (n=80) in solid-dominant cohort. Only solid tumor size was a significant predictor of occult LN metastasis in multivariable logistic regression (OR 1.39 per 5mm increase, 95% CI 1.10-1.77, p = 0.006). Survival analysis revealed a higher rate of freedom from recurrence (p = 0.04) and favorable trends in overall survival (p = 0.09) and recurrence-free survival (p = 0.086) in the GGO-dominant cohort. CONCLUSIONS: The hypothesis that GGO-dominant morphology reliably predicts negative lymph node involvement was not confirmed. These findings support the continued role of surgical nodal assessment for accurate pathological staging.