Lymphatic Spread of Non-Small-Cell Lung Cancer: Mechanisms, Patterns, Staging, and Diagnosis

Lung cancer is the leading cause of cancer-related death worldwide. Lymph node involvement affects staging and, therefore, prognosis. Understanding lymph node drainage, metastatic patterns, and different sampling techniques contributes to the overall care of lung cancer patients. Non-small-cell lung cancer is the most common type of lung cancer; appropriate staging is vital to determine treatment modalities which includes surgery, radiation therapy, chemotherapy, or a combination of these. In this review, we aim to describe the pathogenesis of lymph node metastasis, current guidelines for lymph node sampling, patterns of lymph node spread, new and novel lymph node sampling techniques, and their diagnostic yields.