Serum IL-6 and IL-12 levels in breast cancer patients.

Previous studies indicated that interleukins 6 & 12 are multifunctional cytokines which regulate of immune response and cancer cell proliferation. We measured serum levels of these cytokines in 40 females with breast cancer and examined their correlation with clinicopathological variables including stages of the disease and estrogen and progesterone receptor expression on tumor cells. Serum levels of IL-6 (mean =111.