Expression and prognostic significance of Stat5a and E-cadherin in extramammary Paget's disease

Background: Stat5 has been shown to regulate the proliferation and inhibition of apoptosis in cancer cells. E-cadherin plays an important role in maintaining epithelial stability and is widely regarded as a prognostic marker in many types of human cancers. The expression of Stat5 has not been investigated in extramammary Paget's disease (EMPD). Objectives: To study the expression of Stat5a and E-cadherin protein in EMPD and to evaluate the relationships between them. Methods: Thirty-six tissue samples from 34 cases with primary EMPD were subjected to immunohistochemical staining for Stat5a and E-cadherin. Results: Twenty-nine of 30 in situ EMPD specimens were positive for Stat5a expression, and the staining pattern for Stat5a was mainly nuclear in the majority of Paget's cells. All four invasive specimens and two metastatic lymph node specimens were negative for Stat5a. Twenty-six of 30 in situ EMPD specimens expressed E-cadherin in more than 50% of tumor cells, and three of 30 in situ EMPD specimens expressed E-cadherin in less than 50% of tumor cells. One in situ EMPD specimen and one invasive specimen expressed E-cadherin in less than 25% of tumor cells. Three invasive specimens and two metastatic lymph node specimens were negative, with occasional membranous staining for E-cadherin. There is a significant correlation between the expression of Stat5a and E-cadherin. Conclusions: Our results showed that these proteins were found in in situ lesions, and it is speculated that these proteins may play some role in the prognosis/invasion of EMPD.