The expression of death-associated protein kinase in the progression of breast carcinoma and its significance

Objective: To investigate the possible relationship between the expression of death-associated protein kinase (DAPK) and the breast tumor progression from premalignant in situ to invasive carcinoma. Methods: The expression of DAPK was evaluated by using S-P immunohistochemistry method in 42 cases of breast hyperplasia, 30 cases of breast atypical hyperplasia, 14 cases of non-invasive breast carcinoma, and 68 cases of invasive breast carcinoma. The relationship between DAPK and the pathologically biological features of breast cancer was assessed. Results: The positive rate of DAPK in invasive breast carcinoma was 42.6%, obviously lower than that in hyperplasia (92.9%), atypical hyperplasia (73.3%) or non-invasive carcinoma (71.4%) with statistical significance (P < 0.05). The positive expression rate of DAPK in breast atypical hyperplasia and non-invasive carcinoma was 72.7%, which was lower than that in breast hyperplasia (P<0.05). But there was no significant difference between atypical hyperplasia and non-invasive carcinoma (P>0.05). There might be an association of the expression of DAPK with estrogen receptor, lymph node metastasis, histology and histological grading of breast carcinoma. Conclusion: The results indicate that the reduced expression of DAPK may play an important role in the development and progression of breast carcinoma. The reduction of DAPK illustrates its potential clinical application as a tumor marker for diagnosis and therapy.