Expression of Phosphatase Regenerating Liver-1 in Esophageal Squamous Cell Carcinoma Associated with Metastasis

Expression of PRL-1 protein was examined with immunohistochemistry in 60 cases of esophageal squamous cell carcinoma (ESCC) with matched lymph node metastasis (=40) and 6 cases of esophageal adenocarcinoma. Its association with ESCC metastasis was also explored. The results showed that PRL-1 protein was more frequently expressed in ESCC with metastasis (31/40, 77.5%) than in ESCC without metastasis (10/20, 50%, =.031) and more in metastatic ESCC (39/40, 97.5%) than primary ESCC (68.3%, =.003). PRL-1 protein expression significantly correlated with the stage of ESCC, 79.4% (27/34) in stage III ESCC and 33.3% (1/3) in stage 1 ESCC (=.003). PRL-1 protein was characteristically expressed in the nuclei, in addition to the cytoplasm, of 3 out of 4 (66.7%) poorly differentiated esophageal adenocarcinoma. These findings suggest that PRL-1 may serve as the potential biomarker to predict the metastasis of ESCC and a better biomarker than PRL-3 in the differential diagnosis of poorly differentiated ESCC.