Aim:  It has been well established that the aberrant activation of the Wnt/β‐catenin signal correlates to endometrial endometrioid adenocarcinoma (EEC). As an effector of the Wnt/β‐catenin mediated antiapoptotic signal, the role of Wnt‐induced secreted protein‐1 (WISP‐1) in EEC still remains unclear.

Methods:  We used immunohistochemistry and quantitative real‐time RT‐PCR to examine the expression of WISP‐1, the estrogen receptor (ER) and progesterone receptor (PR) in 86 cases of EEC, with 20 cases of endometrial hyperplasia, 20 of proliferative endometrium and 20 of secretory endometrium used as the control group. We also correlated the expression of WISP‐1 with various clinicopathologic factors and prognostic values in patients with EEC.

Results:  A high expression of WISP‐1 was observed in 26 of the 86 cases of EEC (30.2%). The expression rate of WISP‐1 in EEC was significantly higher than that in secretory endometrium (P < 0.005). Histopathological grades and PR were associated with high WISP‐1 expression (P = 0.002, P = 0.027, respectively). The estimated five‐year survival rate of patients with low‐to‐moderate expression of WISP‐1 was significantly higher than those with high WISP‐1 expression (91.3% vs 65%, P = 0.011). Multivariate analysis revealed that high WISP‐1 expression and positive lymphovascular space invasion were independent prognostic factors for survival.

Conclusions:  High expression of WISP‐1 was related to tumor cell dedifferentiation and PR loss. WISP‐1 might be a new molecular marker to predict the prognosis of patients with EEC.