Detection of the TP53 tumour suppressor gene product and p53 auto-antibodies in the ascites of women with ovarian cancer.

Antibodies against the P53 tumour suppressor gene product are present in the serum of many cancer patients, but with varying frequencies ranging from 0 to 30%. Approximately 15-20% of patients with ovarian carcinoma develop auto-antibodies against p53 that circulate in the serum. Since many ovarian cancer patients develop ascites during their disease, we speculated that p53 antigen and/or p53 auto-antibodies may be present in this biological fluid. Ninety-six ascites fluids from women with primary ovarian cancer and one from a patient with cancer of the breast, which metastasised to the ovaries, were analysed for p53 auto-antibodies. Seventeen ascites fluids (18%) contained auto-antibodies. For 30 of these patients, serum was also available. Auto-antibodies were present in both serum and ascites in 6/30 patients; 22 patients were negative in both ascites and serum; and 2 patients had auto-antibodies only in their serum. All 97 ascites fluids were also analysed for p53 antigen and 7 (7%) were positive. None of the 17 p53 auto-antibodies-positive ascites fluids were positive for p53 antigen suggesting that p53 auto-antibodies may interfere with p53 antigen detection by capturing the antigen. In total, 24 patients (25%) had either p53 auto-antibodies or p53 protein in their ascites fluid. These data demonstrate that p53 auto-antibodies and/or p53 protein are present in ascites and may have some value for tumour diagnosis, prognosis or monitoring.