Alteration of the p53 gene product occurs frequently during the progression of
colorectal cancer. Recently, mutated p53
protein was found to induce the production of anti-p53
antibodies in the serum of patients. The purpose of this study was to evaluate the relationship between p53 status in serum and chemosensitivity in resectable
colorectal cancer patients. A total of 35 patients with primary
colorectal cancer who underwent surgical treatment were examined by chemosensitivity test with the viable
tumor samples using Histoculture Drug Response Assay (HDRA). Serum samples of these patients to test for p53
antibodies were obtained before
tumor resection, and assayed in duplicate by using an
enzyme-linked
immunosorbent assay (ELISA) kit. The inhibition index of
5-FU and CDDP, determined by the HDRA method, in the sero-positive group was significantly lower than that of the sero-negative group (p < 0.01). Furthermore, significant statistical differences in chemosensitivity to
5-FU and CDDP were revealed depending on the presence of serum p53
antibodies. There was no relationship between chemosensitivity assay and
tumor marker positivity or clinicopathological features in these patients. Detection of serum p53
antibodies, which reflects p53 mutations in
tumor tissue, is a simple method which correlates with chemosensitivity, and may contribute to the selection of favorable chemotherapeutic strategies of
colorectal cancer.