Serum p53 antibodies in correlation to other biological parameters of breast cancer.

Breast cancer is the second most frequent cancer of Thai women. Mutation of p53 is a common event in breast cancer. This alteration can result in cellular accumulation of p53 and may also found in serum p53 antibodies (p53-Abs). To clarify prognostic significance of these antibodies, we evaluated p53-Abs in 158 sera of patients with breast cancer. Thirty (19%) patients were found to have p53-Abs. The incidence of p53-Abs tended to be higher in patients with advanced disease group (stages III and IV) than patients with early disease group (stages I and II) (P=0.055). Strong correlations were found between the presence of p53-Abs and p53 protein expression (P<0.001) and lymph node status (P=0.021). The presence of p53-Abs was associated with lack of estrogen (ER) receptor expression (P=0.035) but was not related to progesterone receptor (PR) (P=0.567). In addition, there was a statistically significant correlation between p53-Abs and proliferation associated antigen Ki-67 (P=0.006), but no relation between c-erbB2 oncoprotein and p53-Abs was observed (P=0.112). Additionally, no correlation was noted between the presence of p53-Abs and serum carcinoembryonic antigen (CEA) or carbohydrate antigen (CA15-3). Our findings indicate that p53-Abs appears to be a promising new parameter to evaluate the cellular biology and prognosis of breast cancer.