The effect of Edrecolomab (Mo17-1A) or fluorouracil-based chemotherapy on specific immune parameters in patients with colorectal cancer - A comparative study

Objectives: We investigated the immune profile of patients with resected Dukes' stage C colorectal cancer (CRC), receiving adjuvant therapy with edrecolomab (Mo17-1A) or first-line 5-fluorouracil (5-FU)-based chemotherapy. Patients and Methods: Patients received either 5 doses of Mo17-1A over 13 weeks, or 5-FU/leucovorin, or 5-FU/levamisole over 6 and 12 months, respectively. Peripheral blood was collected postoperatively and 4 months after therapy initiation. Peripheral blood mononuclear cells were tested in the autologous mixed lymphocyte reaction (AMLR), for natural killer (NK) and lymphokine-activated killer (LAK) cell activity. Serum cytokines were quantified by ELISA. Results: Fifty-two patients entered the study. Postoperatively, they exhibited decreased levels of interleukin (IL)-2, interferon-gamma, IL-12, granulocyte-macrophage colony-stimulating factor and IL-15, low cellular immune responses ( AMLR, NK- and LAK-cytotoxicity) and increased levels of IL-1beta, tumor necrosis factor-alpha, IL-6, IL-10 and prostaglandin E-2. After four months of therapy, patients receiving edrecolomab demonstrated enhanced AMLR, NK, LAK activity, increased serum levels of cytokines regulating such responses and reduced levels of acute-phase cytokines and immune suppressors, compared to patients treated with conventional chemotherapy. Conclusions: Postoperative adjuvant therapy with edrecolomab restores the in vivo deficient immune responses of patients with resected Dukes' C CRC despite its clinical ineffectiveness in recent randomized adjuvant trials. These results suggest that further immunological studies with the combination of edrecolomab and chemotherapy are required. Copyright (C) 2004 S. Karger AG, Basel.