Effect of genetic variation in Notch regulator DTX1 on SCLC prognosis compared with the effect on NSCLC prongosis

Deltex‐1 (DTX1) is a negative regulator of the Notch signaling pathway. Here, we investigated the clinical effect of DTX1 rs1732786A > G, which is associated with better prognosis in patients with early‐stage non‐small cell lung cancer (NSCLC), in 261 patients with small cell lung cancer (SCLC). DTX1 rs1732786A > G was associated with a significantly worse chemotherapy response and lower overall survival in the codominant model (odds ratio = 0.42, 95% confidence interval [CI]: 0.26–0.66, P = 2 × 10(−4); hazard ratio = 1.47, 95% CI: 1.17–1.84, P = 0.001, respectively). An in vitro luciferase assay was performed, and the 1732786G allele demonstrated significantly higher promoter activity than the 1732786A allele (P = 2 × 10(−7)). In summary, DTX1 rs1732786A > G was associated with poor prognosis in patients with SCLC as opposed to patients with NSCLC. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: DTX1 rs1732786A > G was associated with better prognosis in patients with early‐stage non‐small cell lung cancer (NSCLC) in our previous study. WHAT THIS STUDY ADDS: DTX1 rs1732786A > G was associated with a significantly worse chemotherapy response and lower overall survival in small cell lung cancer (SCLC).