Variations in blood ghrelin levels in prostate cancer patients submitted to hormone suppressive treatment.

BACKGROUND Ghrelin is a natural growth hormone segretagogue (GHS), involved in the biology of a number of diseases such as lung cancer and prostate cancer. The aim of this study is to assess the relationship existing between ghrelin and testosterone, insulin, and PSA in prostate adenocarcinoma. PATIENTS AND METHODS A patient population and a control population were studied. The former consisted of 18 individuals, age range 50-75 years, with a primary histological diagnosis of prostate adenocarcinoma that were divided into two equal groups of 9 patients each. The control population consisted of 40 normogonadic healthy males aged between 23 and 77 years (average age 43). The first group was treated with oral bicalutamide with a daily dose of 150 mg, while the second group was treated with an intramuscular injection of 11.25 mg of leuprorelin every three months. Total ghrelin was measured with a radio immunological direct method using Phoenix's ghrelin human RIA kit. Intra-assay variance was 8.2% and inter-assay variance was 11.4% . Acylated-ghrelin was measured by applying an extraction method using C18 columns followed by radio immunological dosage with antibody and peninsula tracer. Intra-assay variance was 6.1% and inter-assay variance was 8.7% . All other blood parameters were analysed at the central laboratory of the S. Orsola-Malpighi Polyclinic in Bologna. PSA and testosterone were used to assess response to treatment. The PSA monitoring was achieved with a chemio-luminescence assay method (Roche Modular analytics E 170). Free T was also measured using a direct RIA kit (Diagnostic Systems Laboratories, Inc.). RESULTS In the four months during which patients underwent pharmacological treatment, testosterone values varied significantly (p<0.05) in both groups. No variations (p>0.05) were found for ghrelin, acylated-ghrelin and insulin. CONCLUSION It is concluded that in patients with prostate neoplasms there is no correlation between the variations of circulating levels of ghrelin and those of testosterone.