Prognostic Significance of Mammary Tumor Suppressor Gene MASPIN in Breast Cance

Introduction: Breast cancer is the fifth most common cause of cancer death (after lung cancer, stomach cancer, liver cancer and colon cancer). In 2005, breast cancer caused 502,000 deaths (7% of cancer deaths; almost 1% of all deaths) worldwide. Among women worldwide, breast cancer is the most common cancer.Maspin was recently described as a member of the serpin family or protease inhibitors that is known to be a tumor suppressor gene produci. Loss of Maspin expression has been found in most breast cancer cases and is correlated with cell motility and tumor invasiveness. However, its precise role in human breast cancer remains to be discovered (Mhawech P, 2005).Background: Prognostic factors in predicting outcomes in patients with carcinoma of the breast are limited to the clinico-pathological parameters, including lymph node metastases, grade and stage of the disease.Aim: To determine whether the expression of Maspin protein has a value in predicting patient outcome.Methods: Maspin immunohistochemistry in tissue samples of 92 patients with breast carcinoma were evaluated using the microarray technique.Results: Maspin expression was more frequently found in invasive ductal carcinoma (53.26%) than in invasive lobular carcinoma (9.78%).A nuclear signal was present in 63.79% and a cytoplasmic signal in 36.21% of positive cases.Nuclear staining was related to estrogen (ER) and proges¬terone receptor (PR) positivity (p 0.001), Cytoplasmic staining was related to ER and PR negativity (p 0.0001).High Maspin expression was demonstrated in breast cancers showing high histological grade or lymphocyte-rich stroma (p 0.05). Maspin expression was not associated with overall and disease-free survival rate of breast cancer.Patients with tumors over expressing Maspin gene had significantly shorter relapse-free survival after surgery than patients whose tumors normally expressed or under expressed Maspin (p=0.011).Conclusion: Our study is the first to determine the value of Maspin in breast cancer, Maspin seems to have a potential prognostic value in patients with breast cancer but results should be confirmed with further studies. The prognostic significance of Maspin over-expression persisted 1 Cox multivariate regression analysis (p=0.0024). These findings showed that the Maspin expression level have an important prognostic significance in human breast cancer, and point to Maspin gene as a putative molecular predictor of hormone responsiveness in breast cancer.