BACKGROUND. Patients with cancer often develop anorexia, fatigue, and decreased muscle mass. These signs and symptoms are nonspecific, and they frequently occur in other conditions, including hypogonadism. METHODS. The objectives of this study were 1) to measure testosterone levels in patients with cancer and 2) to examine the correlations between testosterone, tumor necrosis factor-a (TNF-alpha), interleukin-6 (IL-6), insulin-like growth factor-1 (IGF-1), ghrelin levels, and appetite in patients with cancer patients and in a noncancer control group. This was designed as a cross-sectional study in the setting of a university-affiliated Veterans Affairs Medical Center. The study population included 31 male patients with cancer and 25 gender-matched noncancer controls of similar age. The variables total testosterone (cFT), calculated free testosterone (cFT), calculated bioavailable testosterone (cBT), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), TNF-alpha, IL-6, IGF-1, and active ghrelin were measured in fasting morning plasma samples. Appetite was measured according to a visual analog scale. The main outcome measures were cFT and cBT. RESULTS. Cancer patients had mean TT levels simflar to levels in the noncancer control group but significantly lower levels of cFr, cBT, IGF-1, and appetite. SHBG, LH, TNF-a, IL-6, and ghrelin levels were increased in patients with cancer compared with the control group. cFT and cBT levels were correlated inversely with IL-6 and ghrelin levels and were correlated directly with lGF-1 levels and appetite. CONCLUSIONS. Patients with cancer had lower levels of biologically active testesterone. TT was not adequate for the evaluation of hypogonadism, because SHBG levels were increased. A reliable measurement of FT and/or FIT should be used. LH was elevated in the patients with cancer, indicating that low FT levels were caused by primary testicular dysfunction. The authors postulated that high IL-6 or ghrelin levels inhibit testosterone synthesis, although a secondary effect at the hypothalamic-pituitary levels cannot be excluded.
