Serum tumor markers: potential indicators for occult lymph node metastasis in clinical T1 − 2N0M0 small cell lung cancer patients

Abstract In their letter-to-the-editor entitled “Letter to the Editor: Incidence rate of occult lymph node metastasis in clinical T1 − 2N0M0 small cell lung cancer patients and radiomic prediction based on contrast-enhanced CT imaging: a multicenter study”, Prof. Chen et al. provided insightful comments and suggestions on our original study. We appreciate the authors’ feedback and have conducted a preliminary exploration of the predictive value of serum tumor markers (TMs) for occult lymph node metastasis (OLM) in clinical T1 − 2N0M0 (cT1 − 2N0M0) small cell lung cancer (SCLC) patients. The results indicate that neuron-specific enolase (NSE), carbohydrate antigen 125 (CA125), and squamous cell carcinoma antigen (SCC) have potential predictive value for detecting OLM in cT1 − 2N0M0 SCLC patients. Additionally, further exploration and confirmation through prospective, large-scale studies with robust external validation are needed.