Detection of p53 auto-antibodies in the sera of breast cancer patients with a new recurrence using an ELISA assay. Does a correlation with the recurrence free interval exist?

INTRODUCTION

Mutations of the tumor suppressor gene p53 are common in multiple cancer forms, including breast cancer. Data are available that suggest, that the loss of the wild type form of p53 and the appearance of the mutant forms of p53 are correlated with a poorer overall survival rate in patients with breast cancer. The accumulation of the mutant forms of p53 in the cytoplasmatic rooms of the tumor cells leads to the production of human auto-antibodies against these mutant p53 proteins. Therefore, the aim of this study was to analyse and quantify the levels of serum auto-antibodies against p53 protein in patients with an intact immunological system having an active and new recurrence of breast cancer and to compare the obtained results with the recurrence free interval and with established prognostic parameters at the time of first diagnosis, to see if patients with a positive p53 auto-antibody status had a poorer prognosis than those who were p53 auto-antibody positive.

MATERIALS AND METHODS

The ser of 61 patients with breast cancer, who experienced a new, clinical and biophysically identified local or distant recurrence and that showed an intact immunological system were analysed with an ELISA assay of Dianova to determine the concentration of auto-antibodies against mutant p53.

RESULTS

14.5% of the patients showed a positive p53 auto-antibody serum status. The recurrence free interval between the p53 auto-antibody positive and negative patients was almost the same: 4.12 years for the p53 auto-antibody positive patients versus 3.72 years for the p53 auto-antibody negative patients (independent t-test value = 0.224 and p value = 0.824; statistically not a significant difference). When comparing the p53 auto-antibody status with established prognostic parameters we could only find a statistically significant correlation with tumor size. No correlations were obtained when comparing the p53 auto-antibody status with the N- and M status, the ER- and PR status, the menopausal status and the cathepsin-D status.

DISCUSSION

We were able to demonstrate that the expression of serum auto-antibodies against mutant p53 can not be used as a prognostic parameter in patients with breast cancer as the recurrence free interval between the p53 auto-antibody positive and negative patients did not differ. The determination of the auto-antibodies against p53, though easy to perform, is therefore not a test that helps clinicians in their treatment options, but it remains a useful test for the description of the biological mechanisms of breast cancer.