Loss of Expression of the PTEN Gene Product in the Infiltrating Ductal Carcinoma of the Breast and Its Relationship with Clinicopathologic Factors

ABSTRACT

PURPOSE: PTEN is a novel tumor suppressor gene located on chromosomal band 10q23.3. The detection of PTEN mutations in Cowden disease and in breast carcinoma cell lines suggests that PTEN may be involved in mammary carcinogenesis. Among several series of breast carcinomas, the frequency of loss of flanking markers around PTEN is approximately 30 to 40% and the somatic intragenic PTEN mutation frequency is less than 5%. METHODS: The expression of PTEN was stuided immunohistochemically studied in 41 invasive ductal carcinomas of the breast. We examined the correlation between PTEN expression and clinicopathologic factors such as age, tumor size, lymph node metastasis, histologic grade, nuclear grade, stage, as well as estrogen and progesteron receptors. RESULTS: Among the 41 infiltrating ductal carcinomas, studied 7 (17.1%) were immunohistochemically negative, and 19 (46.3%) demonstrated reduced expression. Among the clinicopathologic factors, tumor size, lymph node metastasis, high stage, and negative progesteron receptor displayed a significant relationship with the decrease of PTEN expression, however age, nuclear grade, and estrogen receptor had less of a relationship with PTEN expression. CONCLUSION: These results suggest that PTEN does play some role as a prognostic factor for carcinogenesis, but this hypothesis requires further study.