Clinical significance of serum p53 antibodies in patients with ulcerative colitis and its carcinogenesis

Background: For early detection of ulcerative colitis (UC)-associated colorectal cancer (CRC), surveillance colonoscopy is recommended in UC patients at high risk. However, poor acceptability deteriorates its effectiveness and a suitable marker for selecting patients at high risk is needed. Here we evaluated clinical usefulness of the measurement of anti-p53 antibodies (Abs) by enzyme-linked immunosorbent assay (ELISA) using sera samples from UC patients. Methods: Sera from 286 patients with UC, 82 patients with sporadic CRC, and 63 healthy controls (HC) were obtained. Serum anti-p53 antibodies were detected with ELISA. Immunohistochemical detection was also performed in patients who developed dysplasia or CRC. Results: Serum p53 Ab was positive in 15.0% of UC, while it was positive only in 1.6% of HCs. In sporadic CRCs, 52.4% of 82 patients were positive. In UC patients with disease duration equal to or longer than 8 years, positivity of serum p53 Ab was significantly higher than those in patients with shorter duration. Eight of 13 (61.5%) UC patients with CRC or dysplasia were positive for serum p53 Abs, which was significantly higher than that in patients without neoplasia. All UC patients with CRC were positive for p53 staining, while 2 were negative for serum p53 Ab. Finally, levels of serum p53 Ab had fallen in 4 patients with CRC we could monitor after surgery. Conclusions: This study revealed that p53 Ab developed in the progression of UC-associated CRC but not in all patients with neoplasia, suggesting that serological detection of p53 Abs by ELISA is not suitable in primarily selecting patients at high risk; however, it is helpful in salvaging patients who drop from a surveillance program.