Expression of p53 and Ki-67 immunoreactivity in breast cancer patients.

Abstract

The aim of this study is to investigate the association between p53, Ki-67 expression and hormone receptor status as well as clinicopathological parameters in breast cancer patients. The study group consists of 146 breast cancer patients (stage I to stage III, according to the postoperative TNM classification of UICC, 1997 guideline system) who underwent radical mastectomy with axillary lymphadenectomy between January 1998 and March 2000. The expression of p53, Ki-67, estrogen receptor (ER) and progesterone receptor (PgR) has been evaluated by using standard immunoperoxidase technique. The scoring system has been performed for determination the results of p53 and Ki-67 immunoreactivity. The semiquantitative ER-ICA and PR-ICA scoring system has been used for assessment of staining for ER and PgR. The results from p53 and Ki-67 expression were correlated to hormon receptor status, and to clinicopathological parameters. Statistical significance was determined with x2 test. Strong correlation was found between the values of p53 and Ki-67 (p<0.00001), p53 and ER (p=0.0004), Ki-67 and ER (p=0.0006) as well as ER and PgR (p<0.0001). p53 and Ki-67 expressed additional correlation to the age of the patients (p=0.01). No correlation was found between p53, Ki-67, ER as well as PgR and lymph node involvement or the stage of the disease. The preliminary results of our study suggest that determination of p53 and Ki-67 expression associated to hormone receptor status and some clinicopathological parameters could be helpful in standardizing the protocols for further treatment of breast cancer patients. However, additional investigations with long term follow-up of the patients are needed to clarify the prognostic significance of p53 and Ki-67 immunoreactivity