Assessing the Prognostic Value of Preoperative Carcinoembryonic Antigen-Specific T-Cell Responses in Colorectal Cancer

Current dogma suggests that tumor-reactive IFN-gamma-producing (T(H)1-type) T-cells are beneficial to patient outcome; however, the clinical consequence of these responses with respect to long-term prognosis in colorectal cancer (CRC) is not understood. Here, we compared the utility of preoperative, peripheral blood-derived IFN-(gamma+) T-cell responses specific to carcinoembryonic antigen (CEA), 5T4, or control antigens (n = 64) with tumor staging and clinical details (n = 87) in predicting five-year outcome of CRC patients who underwent resection with curative intent. Although disease recurrence was more likely in patients with stage III tumors, the presence of preoperative, CEA-specific IFN-gamma-producing T-cells identified patients at a statistically significantly greater risk of tumor recurrence following surgical resection, irrespective of tumor stage (odds ratio = 5.00, 95% confidence interval = 1.96 to 12.77, two-sided P < .001). Responses to other antigens, including 5T4, did not reflect outcome. Whilst these results initially appear surprising, they could improve prognostication and help redirect adjuvant treatments.