ABSTRACT
<p><b>OBJECTIVE</b>To examine the influence of chemotherapy with FOLFOX protocol (CT-F) on the immunologic function in patients with advanced colorectal cancer.</p><p><b>METHODS</b>A total of 43 patients with advanced colorectal cancer were included. Patients who received FOLFOX chemotherapy (Group A, n=22) were compared to those who did not(Group B, n=21). Blood was obtained from peripheral vein before chemotherapy (T0), at the time of completion of chemotherapy (T1), and 3 months after completion of chemotherapy (T2) to detect the percentage of regulatory T lymphocytes (CD4+CD25+Foxp3+T cells) in total T lymphocytes using fluorescence activated cell sorter (FACS). The level of Th1/Th2 cytokines in the serum including interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10) and interferon-γ (IFN-γ) were detected by enzyme-linked immunoabsorbent assay(ELISA).</p><p><b>RESULTS</b>The percentage of regulative T lymphocyte was significantly lower at T1, which increased after chemotherapy but was still lower than that at T0 and that in Group B [(4.15±0.56)%, (5.60±0.88)%, and(5.38±0.92)%, all P<0.01]. The levels of IL-4, IL-10 decreased at T1, and increased to the normal level at T2 compared with those at T0 or those in the control group (all P<0.01). In contrast, the levels of IL-2 and IFN-γ increased significantly at T1 and decreased to the normal level at T2 during the entire observation period.</p><p><b>CONCLUSION</b>For patients with advanced colorectal cancer, FOLFOX chemotherapy can decrease the proportion of regulatory T lymphocytes and results in Th1/Th2 cytokine drift to Th1 type. Therefore, FOLFOX may help the release from the anticancer immune inhibition.</p>