Mediastinal lymph node metastasis pattern of subsolid non-small cell lung cancer.

Area of Science:

• Thoracic Surgery
• Oncology
• Pathology

Background:

• Lymph node (LN) dissection is a critical component of lung cancer surgery, influencing resection strategies, particularly for subsolid nodules.
• Understanding LN metastasis patterns in non-small cell lung cancer (NSCLC) is essential for optimizing surgical approaches.
• This study focuses on the distribution of LN metastasis in NSCLC, with a specific emphasis on subsolid nodules.

Purpose of the Study:

• To investigate the distribution patterns of lymph node metastasis in non-small cell lung cancer (NSCLC).
• To analyze lymph node metastasis in relation to tumor location, clinical stage, and subsolid nodule characteristics.
• To inform individualized lymphadenectomy strategies in lung cancer surgery.

Main Methods:

• Retrospective analysis of 6,273 NSCLC patients treated between January 2014 and December 2018.
• Grouping patients based on primary tumor locations and clinical stages.
• Analyzing the incidence and distribution of lymph node metastasis across different regions.

Main Results:

• Lymph node metastasis was observed in 21.62% of NSCLC patients.
• A lobe-specific distribution pattern was noted for mediastinal LN metastasis.
• Subsolid nodules (≤3 cm) with a consolidation-to-tumor ratio (CTR) ≤0.5 showed negligible LN metastasis (<1%), while those with CTR >0.5 had significant metastasis (2.34-6.60%).
• Tumor location influenced specific patterns of mediastinal LN involvement.
• A significantly better prognosis was observed in the CTR ≤0.5 group compared to the CTR >0.5 group (P<0.0001).

Conclusions:

• Subsolid tumors with CTR ≤0.5 exhibit a very low risk of mediastinal LN metastasis, supporting tailored lymphadenectomy.
• Tumors with CTR >0.5 have a significantly higher metastatic risk, necessitating comprehensive LN evaluation.
• These findings aid in refining surgical strategies for NSCLC, particularly for subsolid nodules.