The clinical course of a cancer is influenced by the interaction of tu
mour cells with the patient's immune system. It is thus conceivable th
at immunologicaI parameters may be used as markers of prognostic or pr
edictive value. We report here that increased serum levels of IL-6 is
a signal of poor prognosis and predicts unresponsiveness to immunother
apy in patients with metastatic melanoma. In cervical cancer, IL-6 pro
duced by infiltrating macophages is a marker of invasive cancer. In pa
tients with multiple myeloma, the plasmatic levels of soluble Fc gamma
receptors are markers of the disease, sCD16 being drastically decreas
ed and sCD32 being slightly increased.