Macrophage migration-inhibitory factor levels in serum of patients with ovarian cancer correlates with poor prognosis.

Ovarian cancer is generally thought of as a cancer with poor prognosis. However, prognostic appraisal of the disease is based on tumor stages, surgical features or sensibility towards platinum-based chemotherapy. There are data that also grant immunological parameters such as CD8(+) T-lymphocyte-(CD8 T-cell) infiltration in tumor tissue, a prognostic role. Macrophage migration-inhibitory factor (MIF) has been described as a tumor-derived protein which allows tumor cell immune escape from antitumoral host natural killer (NK) - and CD8 T-cells. This immune escape is functionally based on down-regulation of the receptor natural killer group 2D (NKG2D). We here report that the levels of the MIF protein which is known to be secreted in ascites and serum of patients with ovarian cancer, not only seems to correlate with common prognostic parameters such as tumor stage or platinum sensitivity, but also with CD8 T- and NK-cell infiltration in tumor tissue. We therefore believe that MIF may play a suppressive role in the host antitumor immune response, which may have a negative impact on the course of the disease. The fact that MIF levels in serum of patients at primary diagnosis correlate with platinum sensibility supports the hypothesis that serum MIF levels should be evaluated as a parameter reflecting tumor sensibility towards chemotherapy in early stages of the disease.