Differential levels of serum sCD40L in cancer patients and healthy donors (HD). (A) Elevated serum sCD40L in cancer patients. Serum sCD40L levels in HDs (n = 16) were compared with levels in patients with metastatic breast cancer (Breast Ca, n = 40), metastatic colon cancer (Colon Ca, n = 17), or first-degree (1°) prostate cancer (Prostate Ca, n = 30) before treatment of any kind. (B) sCD40L levels did not change after vaccination with PSA-TRICOM. Levels of sCD40L in 31 metastatic prostate cancer patients' sera before and after treatment with PSA-TRICOM vaccine were analyzed. (C) Association of pretreatment serum sCD40L levels with overall survival (OS) and Halabi-predicted survival (HPS) in prostate cancer patients vaccinated with PSA-TRICOM. Pretreatment serum samples were evaluated and compared for sCD40L between patients who had longer or shorter survival than their HPS. (D) Decrease in sCD40L in serum of prostate cancer patients after a combination of ketoconazole and alendronate treatments. Levels of serum sCD40L were analyzed by ELISA, and statistical analysis was performed using an unpaired t test. **P < .01. NS indicates not significant.