Neoadjuvant Therapy-Associated CDX2 Expression and Its Prognostic Implication in Esophageal Adenocarcinoma

Neoadjuvant chemoradiotherapy followed by surgery is the standard care for locally advanced esophageal adenocarcinoma. However, reliable postoperative prognostic biomarkers are still needed to stratify patients with different clinical outcomes. This study aimed to investigate postneoadjuvant expression changes of CDX2 and its association with histopathological features, biomarkers for targeted therapy, distant metastasis, and survival status. A total of 62 esophagogastrectomy specimens from one institution were evaluated. A tissue microarray was constructed, and IHC staining was performed. CDX2 expression was found in 27 (43.5%) cases with well-to-poor differentiation. Compared with preoperative biopsies, 68.8% of cases demonstrated induced or enhanced CDX2 expression. There were no significant differences in age, tumor location, histologic grade, lymph node metastasis, tumor stage, and treatment response between CDX2-positive and CDX2-negative groups. Neuroendocrine and Paneth cell differentiation induced by neoadjuvant therapy were more commonly seen in CDX2-positive cases. CDX2 expression was associated with higher multidrug resistance-1 and HER-2 expression. Patients with CDX2-positive diseases showed a higher risk of distant metastasis and a worse prognosis than those with CDX2-negative diseases.