The overexpression of mutant p53 stimulates serum p53 antibody production in patients with colorectal carcinoma even in superficial tumors. Although the short-term perioperative monitoring of serum p53 antibody titers is reported to be useful in predicting tumor recurrence and patient survival in colorectal carcinoma, the clinical utility of the long-term monitoring of serum p53 antibody titers in patients with colorectal cancer remains unknown. Here, we report the 3-year monitoring of serum p53 antibody titers in a 60-year-old man with rectal cancer, clinical stage IV (T2N2M1b, lung and liver metastases), who was treated with chemotherapy and surgery. Screening tests for CEA (29.4 ng/ml), CA19-9 (41.1 U/ml), and serum p53 antibody (2170 U/ml) were positive before treatment. After chemotherapy with mFOLFOX6 + bevacizumab (B-mab), CEA and CA19-9 decreased to the normal range. However, serum p53 antibody titer remained positive (283 U/ml). After low anterior resection, the serum p53 antibody titer still remained positive (63.4 U/ml). Serum p53 antibody titer significantly changed and was associated with treatment response and tumor recurrence. In the last 6 months of the patient's life, serum p53 antibody titer gradually decreased, which possibly reflects the modification of the patient's immune response to p53 antigens.
Keywords: Liver metastases; Lung metastases; Rectal cancer; Serum p53 antibody.