Uselessness of Serum p53 Antibody for Detecting Colitis-associated Cancer in the Era of Immunosuppressive Therapy

BACKGROUND/AIM

The present study examined the utility of serum p53 antibody (Ab) for detecting colitis-associated cancer (CAC) in the era of immunosuppressive therapy.

PATIENTS AND METHODS

Two hundred and fifty patients were analyzed, 219 had no carcinoma or dysplasia (Group non-CAC), and 31 had carcinoma or dysplasia (Group CAC). Serum p53 Abs were detected with an enzyme-linked immunosorbent assay. Immunohistochemical detection was performed in Group CAC.

RESULTS

Immunosuppressive therapy was performed in 98.1% of Group non-CAC and 80.6% of Group CAC. There were no differences in serum p53 Abs positivity between Groups non-CAC and CAC (8.7% vs. 3.2%, p=0.30). p53 staining positivity was noted in 90.3% of Group CAC, and the rate of serum p53 positivity was significantly lower in patients with immunosuppressive therapy than in those without in Group CAC (0.0% vs. 16.7%, p=0.04).

CONCLUSION

The utility of serum p53 Ab for detecting CAC is dubious in the era of immunosuppressive therapy.

Serum anti-p53 antibodies in gastric adenocarcinoma patients are associated with poor prognosis, lymph node metastasis and poorly differentiated nuclear grade

Mutation of the p53 tumour suppressor gene often leads to the accumulation of mutant p53 protein in tumour cells. Many cancer patients develop antibodies that recognize the overexpressed p53 protein. The presence of these antibodies is, in some tumour types, associated with poor prognosis. Gastric cancer is a highly prevalent disease associated with a high rate of mortality, there is a need for improved clinical and biological markers for disease behaviour. To investigate the clinical relevance of serum anti-p53 antibodies in patients with gastric adenocarcinoma, we have examined the sera of 501 gastric cancer patients for the presence of serum antibodies against the p53 protein. By immunoblotting analysis using a cell lysate containing overexpressed p53 protein as well as affinity-purified recombinant p53 protein as antigens, we have detected anti-p53 antibodies in 11.2% (61 of 501) of gastric cancer patients, but in none of 46 cancer-free individuals. The presence of anti-p53 antibodies was tightly associated with tumours of higher nuclear grade and lymph node metastasis, and a negative association was found between the presence of anti-p53 antibodies and survival. These results suggest that a preoperative test of serum anti-p53 antibodies in gastric cancer patients can be useful to identify subset of patients who may need gastrectomy with lymph node dissection and post-operative adjuvant therapy.