Cytoplasmic poly(A)-binding protein 1 as a biomarker to assist early diagnosis and prognosis of esophageal squamous cell carcinoma in endoscopic biopsy fragments.

OBJECTIVE: Esophageal squamous cell carcinoma (ESCC) has high mortality worldwide, but its early diagnosis and prognosis are very difficult. Cytoplasmic poly(A)-binding protein 1 (PABPC1) plays an important role in regulating most cellular processes, resulting in a close relationship to tumor genesis and malignant development. Therefore, this work aimed to evaluate the clinical value of PABPC1 as a biomarker for the early diagnosis and prognosis of ESCC in endoscopic patients. METHODS: A total of 185 patients with lesions found by endoscopy were involved in this study, including 116 finally diagnosed with ESCCs and 69 with nonmalignant lesions. Biopsy fragments and surgical specimens were collected to assess PABPC1 expression by immunohistochemistry, and the association between the expression and survival was analyzed and compared in both samples. RESULTS: The average ratio of positive tumor cells to total tumor cells in the biopsy fragments was lower than that in surgical specimens, leading to a cutoff value of only 10% for the former in ROC analysis (AOC = 0.808, P < 0.001). However, PABPC1 high expression (PABPC1-HE) in both biopsy fragments and surgical specimens was associated with poor survival. When PABPC1 expression was used as a biomarker to diagnose ESCC in biopsy fragments, sensitivity, specificity, positive predictive value, and negative predictive value reached 44.8, 100.0, 100.0, and 51.9%, respectively. Among the 116 ESCC patients, 32 received postoperative concurrent chemoradiotherapy. Postoperative treatment increased the overall survival (OS) but not disease-free survival in lymph node-positive patients (P = 0.007 and 0.957, respectively). Nevertheless, PABPC1-HE predicted shorter OS regardless of the postoperative treatment in both endoscopic biopsy samples and surgical specimens. CONCLUSION: PABPC1 expression can be used as a biomarker to detect ESCC from endoscopic lesions. At the same time, PABPC1-HE is a predictor of poor survival regardless of postoperative chemoradiotherapy in endoscopic biopsy samples of ESCC.