Luteinizing hormone-releasing hormone antagonist cetrorelix as primary single therapy in patients with advanced prostatic cancer and paraplegia due to metastatic invasion of spinal cord

Abstract

Objectives. To assess the clinical response to luteinizing hormone-releasing hormone (LH-RH) antagonist cetrorelix (SB-75) in patients with advanced carcinoma of the prostate and paraplegia due to mestastatic invasion of spinal cord. Methods. Cetrorelix was given at two different dose regimens to 5 patients with prostatic cancer Stage D2 and paraplegia. Urologic and neurologic examinations, laboratory studies, radiography (myelography), and prostate ultrasonography were carried out. Prostate-specific antigen (PSA) and free testosterone were also measured. Results. In all patients, the neurologic symptoms regressed. The recovery of the thermic and vibratory sensation and motility of the toes was observed. The neurologic improvement continued during the treatment and at 3 months all the patients were able to walk with the aid of a cane. In 1 patient, the myelography showed that the spinal cord compression had disappeared and prostate volume assessed by ultrasonography showed a significant decrease. The bladder function greatly improved in all 5 patients during the treatment with cetrorelix. Baseline levels of luteinizing hormone fell from 9.28 to 1.0 IU/L and those of follicle-stimulating hormone (FSH) fell from 18.28 to 12 IU/L ( P < 0.05) after the first day of therapy with cetrorelix. Mean levels of free testosterone were reduced from 52.4 to 14.7 pmol/L ( P < 0.005) at 12 hours and to 13.1 pmol/L ( P < 0.005) 3 days after the first injection of cetrorelix. A persistent inhibition of gonadotropins and testosterone was maintained during the subsequent 3 months of therapy. The high levels of PSA gradually decreased. Conclusions. Our results show that LH-RH antagonist cetrorelix causes an immediate lowering of the serum testosterone levels in patients with prostate cancer and metastases in the spinal cord, in whom the LH-RH agonists cannot be used as single drugs because of the possibility of flare-up and appears to be appropriate for long-term therapy.