Importance of Lymph Node Evaluation in ≤2-cm Pure-Solid Non-Small Cell Lung Cancer

Area of Science:

• Thoracic Surgery
• Oncology
• Pulmonary Medicine

Background:

• Lymph node (LN) metastasis prevalence in small lung cancer depends on tumor size and ground-glass opacity.
• Investigating occult LN metastasis and prognosis in small non-small cell lung cancer (NSCLC), particularly pure-solid tumors.

Purpose of the Study:

• To evaluate the impact of tumor characteristics on lymph node metastasis in small NSCLC.
• To compare prognosis between mixed ground-glass nodules (mGGN) and pure-solid nodules (PSN) in NSCLC.

Main Methods:

• Retrospective review of ≤2-cm clinical N0 NSCLC patients undergoing curative resection (2003-2017).
• Analysis of patients with complete systematic LN dissection, comparing mGGN and PSN groups.
• Evaluation of pathological results and disease-free survival.

Main Results:

• Tumor size did not affect LN metastasis in mGGN (2.18-2.27%).
• LN metastasis significantly increased with tumor size in PSN (2.67% to 21.31%).
• PSN group had poorer 5-year disease-free survival (71.2%) compared to mGGN (94.4%).

Conclusions:

• Tumor size is a significant predictor of nodal metastasis in PSN, but not mGGN.
• Thorough LN dissection is recommended for small NSCLC, especially pure-solid tumors ≥ 1 cm.
• mGGN offers a better prognosis than PSN in small NSCLC.