Interleukin 6 Is Associated with Cachexia in Patients with Prostate Cancer

Objectives: To evaluate the relationship between serum interleukin (IL)-6 and cachexia in patients with prostate cancer. Methods: Serum levels of IL-6, total protein, albumin, total cholesterol, and hemoglobin concentration were determined in 164 blood samples from patients with prostate cancer. The body mass index and performance status were also determined. Results: The serum total protein, albumin, and cholesterol levels, hemoglobin levels, and body mass index of the patients whose serum IL-6 level was 7 pg/mL or greater were significantly lower (P <0.05) than the corresponding values in patients with a serum IL-6 level of less than 7 pg/mL. The serum IL-6 level of patients with a serum albumin level of less than 3.5 g/dL, serum total protein level of less than 7.0 g/dL, serum total cholesterol level of less than 180 mg/dL, hemoglobin level of less than 11.0 g/dL, and body mass index of less than 21 kg/m² were significantly greater (P <0.05) than the values in their respective counterparts. A significant correlation was found between the elevation of serum IL-6 and performance status (P <0.05). The mortality rate of patients with greater serum IL-6 levels was significantly greater than that of those with lower serum IL-6 levels in patients with untreated disease, patients in remission, and patients with relapse (all P <0.05). Conclusions: These findings suggest that IL-6 may be one of the factors contributing to the complex syndrome of cachexia in patients with prostate cancer (all P <0.05).