SERUM LEVELS OF GONADOTROPINS AND TESTOSTERONE DURING THE COURSE OF TREATMENT FOR A CASE WITH GONADOTROPIN SECRETING TESTICULAR TUMOR

Abstract

A case (37yr.) of testicular tumor with a histological picture of seminoma mixed with some syncytial cell elements was studied for changes of serum lutenizing hormone (LH), follicle stimulating hormone (FSH) and testosterone levels before removal of the tumor, during postoperative treatment by ⁶⁰Co-irradiation and anticancer chemotherapy with Actinomycin-D, and thereafter for the subsequent follow-up period of two years. The measurement of serum LH, FSH and testosterone was performed by radioimmunoassay. The serum LH level before the treatment was increased to an abnormally high level, probably reflecting chorionic gonadotropin (HCG) secreted by the tumor. HCG has been shown to be strongly cross reactive with the LH preparation in radioimmunoassay. The LH level was decreased within normal limits immediately after the removal of the testicular neoplasm. The serum FSH level, on the other hand, was undetectable before surgery, but it increased gradually toward the normal range after the operation, in contrast with the marked decrease in the LH level. The markedly depressed serum FSH level before the removal of the tumor may be explained either by the pituitary-gonadal feedback mechanism through steroid hormones (androgens or estrogens) probably secreted by the Leydig cells stimulated by the tumor originated HCG, or by the so-called short feedback mechanism in which HCG exerted negative feedback control on the hypothalamic center.
The serum LH and FSH levels which were normalized transiently after orchiectomy, rose again during the postoperative treatment by radiotherapy and anticancer chemotherapy. The elevation in FSH was observed earlier and more distinctly than that in LH. These elevated serum LH and FSH concentrations were completely suppressed by administration of exogenous testosterone and increased further in good response to synthetic lutenizing hormone-releasing hormone (LH-RH). Thus the increased serum gonadotropins after the removal of the tumor were concluded to be not of tumor origin but of pituitary origin. On the other hand, serum testosterone which had remained within the normal range before the removal of the tumor was lowered during the courses of the postoperative therapy. Seminalysis performed 9 months after orchiectomy revealed no sperm in the ejaculate. The increases of serum gonadotropin levels after the treatment were considered as a result mainly of testicular dysfunction affected by the postoperative irradiation and anticancer chemotherapy. The patient is enjoying a good health for two years after surgery with no sign of tumor recurrence and with a tendency toward normalization of serum LH, FSH and testosterone levels and an improvement of sperm count.