Impact of the EpCAM expression on biochemical recurrence-free survival in clinically localized prostate cancer

The epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein that was originally identified as a marker for carcinoma, attributable to its high expression on rapidly proliferating tumors of epithelial origin. The role of EpCAM is not limited to cell adhesion but includes diverse processes such as signaling, cell migration, proliferation, and differentiation.

Several studies investigated EpCAM expression in prostate carcinoma but none of them confirmed its prognostic role. The aim of our study was to investigate EpCAM expression and its relationship with established prognostic features in prostate carcinoma.

The study included a cohort of 102 patients treated with radical prostatectomy for clinically localized prostate carcinoma. Immunohistochemistry was performed to evaluate the EpCAM expression in prostate cancer and non-neoplastic prostate tissue. The percentage of positively stained carcinoma and benign glands was examined in the whole mount of the chosen slide.

The extent of EpCAM expression was significantly higher in malignant than in benign prostatic tissue (P < 0.001). EpCAM expression in prostate cancer was associated with established features indicative of worse prognosis, such as preoperative (P = 0.009) and postoperative (P = 0.004) Gleason score and follow-up time (P < 0.001). Patients with higher preoperative and postoperative Gleason score and short follow-up time had tumors with a significantly higher expression of EpCAM. Negative correlation of follow-up time and EpCAM expression indicated that tumors in patients with biochemical recurrence (BCR) harbored higher EpCAM expression. Moreover, expression of EpCAM was significantly higher in patients with BCR compared with patients without BCR (P < 0.001). Tumors in T3 stage of the disease showed significantly higher EpCAM expression compared with T2 tumors (P = 0.002). Univariate (P < 0.001) and multivariate (P < 0.001) analyses showed that EpCAM expression was a significant predictor of shorter biochemical recurrence free-survival.

Our results confirmed high level of EpCAM expression in prostate cancer and support its potential role in prostatic cancer progression. In addition, EpCAM could serve as an additional prognostic marker for the recognition of patients with an increased risk of disease recurrence that need introduction of secondary therapy.