Purpose: Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is one of the most frequently mutated human tumor suppressor genes. The present study aims at investigating role of PTEN mutation in breast carcinogenesis by analyzing PTEN mutation spectrum and PTEN protein expression in selected benign breast lesions versus breast cancer as regards comparison between PTEN immunohistochem-ical expression and PTEN mutations in studied cases.
Patients and Methods: Fifty cases of breast lesions including 30 non-consecutive retrospective selected breast carcinoma (10 cases in-traductal breast carcinoma (DCIS). 20 cases of invasive breast ductal carcinoma) and 20 cases of benign proliferative breast lesions (10 fibro-adenoma, 10 fibrocystic disease). 10 cases ofnon- neoplastic breast tissue adjacent to selected lesions were taken as control. Cases were collected in the period 2004-2010, selected from files of pathology department, faculty of medicine- Benha University and Egyptian national cancer institute (NCI).
Results: highly significant inverse correlation between PTEN immuno/expression and types of the disease (P<0.01). There is highly significant inverse correlation between PTEN expression and IDC grade, pathologic stage (P<0.01) as well as significant inverse correlation with lymph node status (P<0.05). Similarly, there is highly significant inverse correlation between inactivated/ lost PTENDNA and tumor type as well as DCIS grade (P<0.01). There is significant inverse correlation between lost PTEN DNA and tumor grade& lymph node status, (P < 0.05).
Conclusion: PTEN is a negative cell cycle regulator and it is involved in early breast carcinogenesis by inactivated/ lost its expression as examined by both immunohistochemistry and PCR testing with significant values as regard tumor type, grade, lymph node status which can be used during therapy and patient's follow up.
Key words: Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), Duct carcinoma in situ (DCIS), tumor suppressor gene (TSG), invasive duct carcinoma (IDC), polymerase chain reaction (PCR).
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