Evaluation of CCL18 and S100A4 as biomarkers in small cell lung cancer (SCLC) progression and response to therapy

<bold>Introduction:</bold> Small cell lung cancer (SCLC) is an aggressive form of lung cancer known for its rapid growth and early metastasis, which makes early detection and treatment difficult. Identifying reliable biomarkers is key for improving diagnostic and therapeutic approaches. CCL18, involved in immune modulation, and S100A4, associated with tumor progression, may provide insights into the biological behavior of SCLC and patient outcomes. This study aims to evaluate their levels in SCLC patients compared to healthy controls and investigate correlations with tumor markers, TNM classification and survival to determine their clinical utility in the treatment of SCLC. <bold>Methods:</bold> Serum levels of CCL18 and S100A4 were measured in 26 SCLC patients and 16 healthy controls by ELISA to investigate their correlation with tumor markers NSE, CEA, CYFRA21-1, TNM classification, and survival outcomes. <bold>Results:</bold> A significant increase in CCL18 (median: 180.09 ng/ml in patients vs. 70.61 ng/ml in controls, p<0.0001) and S100A4 (median: 13.60 ng/ml in patients vs. 2.80 ng/ml in controls, p<0.0001) was observed. CCL18 showed a strong correlation with NSE (r=0.65, p=0.008), but not with survival, while the correlation of S100A4 with tumor size and M-stage was positive, but not statistically significant. <bold>Conclusion:</bold> Elevated levels of CCL18 and S100A4 in SCLC patients indicate their potential as diagnostic markers. The correlation of CCL18 with NSE indicates its utility in monitoring disease progression. However, the prognostic value of these markers, particularly in terms of survival, requires further investigation with an expanded patient cohort to draw more definitive conclusions.