The cyclin dependent kinase inhibitor p27 and its prognostic role in breast cancer

p27 is an inhibitor of cyclin dependent kinase involved in the regulation o f the cell cycle. In this commentary we discuss the current knowledge on p2 7 in breast cancer and its significance in predicting the outcome. p27 prot ein levels are high in most cases of breast carcinomas, are correlated with the levels of cyclin D1 and estrogen receptor, and could be a useful predi ctor of survival, because they are low in aggressive carcinomas. Immunodete ction of p27 in breast tumors could be useful in the assessment of prognosi s, especially in those cases in which the commonly used parameters are insu fficient, and might ultimately influence the therapy of this disease.