Correlation of DLL3 Expression with Platinum-based Chemotherapy Efficacy and Prognosis of Advanced Small Cell Lung Cancer

Objective To explore the association between DLL3 expression and chemosensitivity of advanced SCLC patients to cis-platinum/etoposide therapy, and to evaluate the prognostic value of DLL3.

Methods We selected 64 patients diagnosed as stage Ⅲ/Ⅳ SCLC. Protein levels of DLL3 were examined by immunohistochemistry. χ² test was used to analyze the relation between DLL3 expression and chemotherapy efficacy. Kaplan-Meier and Cox multivariate analysis were used to investigate the impacts of DLL3 and other factors on PFS and OS of advanced SCLC patients.

Results DLL3 was detected in 84.1% (54/64) of the samples and not associated with gender, age, smoking history or stage (P > 0.05). The response rate(RR) and disease control rate in DLL3-high group were lower than those in DLL3-low group (P < 0.05); PFS of patients with low DLL3 expression were better than those with high DLL3 expression (P < 0.05). DLL3 expression, tumor stage and tumor diameter were independent prognostic factors for PFS, and tumor stage was an independent prognostic factor for OS of advanced SCLC patients.

Conclusion DLL3 is related to the response rate of EP chemotherapy and PFS. It may become a biomarker for predicting chemosensitivity. DLL3 has no predictive value for long-term prognosis of patients with advanced SCLC.