Loss of PTEN expression is associated with metastatic disease in patients with endometrial carcinoma

BACKGROUND: The PTEN tumor suppressor gene frequently is involved in endometrial carcinoma. Loss of heterozygosity and mutations reportedly are common, although the biologic importance of these changes remain largely unknown. The objective of this study was to assess the pattern of PTEN expression by immunohistochemistry in a large series of patients with endometrial carcinoma. METHODS: A population-based series of 316 patients with endometrial carcinoma who had long and complete follow-up was investigated for PTEN expression and its correlation with clinicopathologic variables, tumor markers, and survival. RESULTS: PTEN protein expression was mainly cytoplasmic in tumor cells, with no expression seen in 56 of 279 patients (20%) who had evaluable results. A heterogeneous staining pattern was found in 70 tumors (25%). A significant association between the loss of PTEN expression and metastatic disease was identified (P = 0.05). However, PTEN staining did not influence survival significantly. CONCLUSIONS: The loss of PTEN expression is relatively frequent in endometrial carcinoma and is associated significantly with metastatic disease. This indicates that the PTEN system plays an important role in some endometrial carcinomas, but further studies of PTEN protein expression related to various genetic alterations are necessary.