Pancreatic ductal adenocarcinoma is a highly malignant tumor with poor prognosis, and the biomarkers for the early diagnosis, targeting therapy, and prognosis are still not clinically available. This study investigated the expression of forkhead box P1 and forkhead box O3a proteins in human pancreatic ductal adenocarcinoma tumor tissues and pancreatic tissues with and without benign lesions using immunohistochemical staining. Results showed that the positive rates of forkhead box P1 and forkhead box O3a protein expression were significantly lower in pancreatic ductal adenocarcinoma tumors compared to peritumoral tissues, benign pancreatic tissues, and normal pancreatic tissues (p < 0.01). Pancreatic tissues with negative forkhead box P1 and forkhead box O3a protein expression exhibited dysplasia or intraepithelial neoplasia. The positive rates of forkhead box P1 and forkhead box O3a expression were significantly lower in cases with tumor mass >5 cm, lymph node metastasis, invasion to surrounding tissues and organs, and tumor-node-metastasis III + IV stage disease compared to cases with tumor mass ⩽5 cm (p < 0.05), no lymph node metastasis (p < 0.001 and p = 0.001, respectively), no invasion (p = 0.003 and p = 0.004, respectively), and tumor-node-metastasis I or II stage disease (p < 0.05). Kaplan-Meier survival analysis showed that pancreatic ductal adenocarcinoma patients with negative forkhead box P1 and forkhead box O3a expression survived significantly shorter than patients with positive forkhead box P1 and forkhead box O3a expression (p = 0.000). Cox multivariate analysis revealed that negative forkhead box P1 and forkhead box O3a expression was an independent poor prognosis factor in pancreatic ductal adenocarcinoma patients. The area under the curve of a receiver operating characteristic curve was 0.642 for forkhead box P1 (95% confidence interval: 0.553-0.730) and 0.655 for forkhead box O3a (95% confidence interval: 0.6568-0.742). Loss of forkhead box P1 and forkhead box O3a protein expression is associated with carcinogenesis, progression, and poor prognosis in patients with pancreatic ductal adenocarcinomas.
Keywords: Pancreatic ductal adenocarcinoma; dysplasia; forkhead box O3a; forkhead box P1; immunohistochemistry; pancreatic intraepithelial neoplasia.