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 =111.38 pg/ml) as well as IL-12 (mean=1142.75 pg/ml) were significantly increased in breast cancer patients as compared to controls (mean 1.75 pg/ml &19.90 pg/ml respectively). A statistically significant correlation was found between levels of IL-6 as well as IL-12 and progression of the tumor (P < 0.05). However, no statistical difference was found in serum levels of these cytokines between metastatic and non-metastatic cases. Both cytokines negatively correlated with estrogen and progesterone receptor expression on tumor cells. In conclusion, serum levels of IL-6 and IL-12 are highly elevated in breast cancer patients and correlate with tumor progression. Assays for serum levels of IL-6 and IL-12 can be used as predictive non-invasive tests for tumor progression in breast cancer patients.