Wang J, Yu L, Sun Y, et al. - Findings demonstrate excellent detection performance of a chemiluminescent enzyme immunoassay (CLEIA) for cystatin SN (CST1) protein, which might serve as a prospective serological biomarker for early diagnosis of esophageal squamous cell carcinoma (ESCC).

• In a pilot study, a high expression of CST1 protein in ESCC tissues has been shown.

• This study involved 112 early ESCC, 107 esophageal benign lesions, and 151 healthy controls.

• CLEIA developed in this study showed linear range and detection limit of 6.25– 400 pg/mL and 1.35 pg/mL, respectively, for CST1; average recovery rate was 102.65%; coefficients of variation of intra-batch precision and inter-batch precision were < 1/4 total error allowance (TEa) and < 1/3 TEa, respectively; and good sample and reagent stability.

• CST1 had a diagnostic sensitivity of 31.25% for early ESCC (specificity 92.64%, AUC 0.654).

• Conventional tumor markers showed diagnostic sensitivity ranging from 16.07% to 28.57%, at > 93.0% specificity, and SCC-Ag demonstrated the highest AUC (0.709).