Predictive model based on folate receptor-positive circulating tumor cells in neoadjuvant immunochemotherapy for esophageal cancer

Background: Effective biomarkers for predicting outcomes in patients with esophageal squamous cell carcinoma (ESCC) receiving neoadjuvant immunochemotherapy (nICT) remain limited. In this study, we investigated the prognostic value of baseline folate receptor-positive circulating tumor cells (FR-CTCs) in locally advanced ESCC. Methods: This cohort study retrospectively analyzed ESCC patients who underwent nICT between August 2020 and August 2023. Factors associated with disease-free survival (DFS) were evaluated using univariable and multivariable Cox proportional hazards regression. Candidate variables were further screened by univariable Cox and least absolute shrinkage and selection operator regression to construct a predictive model. A nomogram incorporating FR-CTCs levels and key clinical parameters was developed and comprehensively assessed for discrimination, calibration, and clinical utility. Results: Analysis of clinical data from 64 patients identified baseline FR-CTCs level emerged as a strong and independent predictor of postoperative recurrence. FR-CTCs were significantly associated with DFS when analyzed as either a continuous or categorical variable. As a continuous variable, each one-unit increase in FR-CTCs level was associated with an increased risk of recurrence both before [hazard ratio (HR) =1.26, 95% confidence interval (CI): 1.12-1.42; P