Immunomodulatory changes in patients with colorectal cancer

Abstract.

Background and aims: Solid tumors are frequently accompanied by a depressed cellular and humoral immunity. This study analyzed changes these factors in colorectal cancer patients. Patients and methods: We compared cellular (leukocytes, lymphocytes, HLA-DR expression on monocytes) and humoral immune parameters (interleukin-6, interleukin-10, tumor necrosis factor α) in 40 patients with colorectal cancer and in 18 healthy controls. Results: Leukocytes were in the normal range in patients and controls. However, tumor patients showed significant lymphopenia in comparison to controls. HLA-DR antigen expression on CD14⁺ monocytes was reduced in the cancer patients while IL-6 and IL-10 plasma levels were increased. Patients with UICC stage III had IL-6 and IL-10 concentrations were significantly increased as well. Conclusions: These findings suggest that colorectal tumor establishment and progression results in a malfunction of the immune system, and underline the importance of elucidating in detail the mechanisms of immune modulation in cancer patients.