Decreased levels of the cell-cell adhesion molecule E-cadherin are associated with loss of differentiation in a number of human carcinomas. However, the value of E-cadherin as a prognostic marker in these cancers is largely undetermined. A previous study of E-cadherin levels in prostate cancer revealed that almost 50% of tumors examined had reduced or absent levels of this protein (Umbas et al., Cancer Res., 52: 5104–5109, 1992). To determine the potential prognostic significance of this finding, prostate cancer specimens from 89 patients were evaluated immunohistochemically for E-cadherin expression, and the results were related to histopathological grade, tumor stage, presence of metastases, and survival.
As previously observed, a significant inverse correlation was found between E-cadherin expression and tumor grade. Importantly, we also found significant correlations between E-cadherin expression and tumor stage and overall survival. Sixty-three percent of the tumors that extended beyond the prostate capsule (T3–4) versus 33% of the tumors confined to the prostate (T1–2) had aberrant expression (χ2 = 8.1, P < 0.005). Seventy-six percent of the primary tumors from patients that presented with metastases showed aberrant staining compared to 32% from patients without metastases (χ2 = 14.9; P < 0.001). The life table analysis showed a significantly higher survival rate for patients with normal staining compared to patients with aberrant expression (χ2 = 20.4, P < 0.001 by log rank test). Moreover, abnormal expression of E-cadherin correlated significantly with progression after radical prostatectomy (P < 0.005). These results suggest that E-cadherin expression can serve as a prognostic indicator for the biological potential of prostate cancer.
Supported by Grants NUKC 9001 and 9281 from the Dutch Cancer Foundation, Van Deventer Maas Stichting (R. U.).