Application of liquid biopsy in differentiating lung cancer from benign pulmonary nodules (Review)

The diagnosis of malignant and benign pulmonary nodules has always been a prominent research topic. Accurately distinguishing between these types of lesions, particularly small or ground glass nodules, is crucial for the early detection and proactive treatment of lung cancer, ultimately leading to improved patient survival. Although various imaging methods and tissue biopsies have advanced the diagnostic efficacy of pulmonary nodules, each approach possesses inherent limitations. In recent years, there has been a growing interest in liquid biopsy as a non‑invasive and easily obtainable alternative. Furthermore, in‑depth investigations into the mechanisms underlying tumor initiation and progression have contributed to the development of circulating biomarkers for monitoring treatment response and efficacy in lung cancer. This review provides a comprehensive overview of the current landscape of pulmonary nodule diagnosis while highlighting the latest advancements in liquid biopsy techniques, such as extracellular vesicles, tumor‑educated platelets, non‑coding RNA, circulating tumor DNA and circulating antibodies.