The median level of IL-6 increased proportionally with the stage of the cancer (the median level of IL-6 in stage 2a 5.6 ± 1.5 pg/ml, stage 2b 11.7 ± 4.4 pg/ml, stage 3a 16.9 ± 4.7 pg/ml, stage 3b 19.1 ± 4.8 pg/ml, stage 3c 26.3 ±7.0 pg/ml and stage 4 39.8 ±9.4 pg/ml), and this difference was statistically significant (P < 0.001). Here, IL6 is linked to cancer.