Prolactin-secreting tumors in men: surgical cure

Clinical, Pathological, and Molecular Factors of Aggressiveness in Lactotroph Tumours

The behaviour of lactotroph tumours varies between benign tumours, those cured by treatment, and that of aggressive tumours, and carcinomas with metastasis. Identification of clinical, pathological and molecular factors is essential for the early identification of patients that may have such aggressive tumours. Plasma prolactin levels and tumour size and invasion, per se, are not prognostic factors. However, tumours appearing at a young age (<20 years), especially in boys, and the presence of genetic predisposition have a poorer prognosis. In addition, lactotroph tumours in men differ from those in women, being larger, more often invasive, and resistant to dopamine agonists. They are also more often high-grade with a high risk of recurrence and malignancy. The expression of estrogen receptor α is lower than in women and is closely correlated to aggressiveness. Proliferation markers (Ki-67 expression: ≥3%, mitotic count n > 2) are correlated to invasion and proliferation, but, taken alone, their prognostic value is debatable. Based on a 5-tiered clinicopathological classification, and taking into account invasion and proliferation, a grade 2b (aggressive) lactotroph tumour has a 20× risk of progression compared to a grade 1a (benign) tumour. Moreover, lactotroph tumours are the second-most frequent aggressive and malignant tumour. Other factors, such as the expression of growth factors (vascular endothelial growth factor [VEGF] and epidermal growth factor [EGF]), the genes regulating invasion, differentiation and proliferation, adhesion molecules (E-cadherin), matrix metalloproteinase 9, and chromosome abnormalities (chromosomes 11, 19, and 1), have also been correlated with aggressiveness. Currently, clinical signs, a prognostic classification, and molecular and genetic markers may all help the clinician in the early identification of aggressive lactotroph tumours and enable stratification of their management.

Expression of estrogen receptor alpha is associated with prolactin pituitary tumor prognosis and supports the sex-related difference in tumor growth

CONTEXT

A sex difference in the progression of prolactin (PRL) tumors has been disputed for years.

OBJECTIVE

To compare tumor characteristics and postoperative clinical course between men and women, and correlate data with estrogen receptor alpha (ERα (ESR1)) expression status.

DESIGN, PATIENTS, AND METHODS

Eighty-nine patients (59 women and 30 men) operated on for a prolactinoma and followed for at least 5 years were selected. Tumors were classified into five grades according to their size, invasion, and proliferation characteristics. The ERα expression was detected by immunohistochemistry and a score (0-12) calculated as the product of the percentage of positive nuclei and the staining intensity.

RESULTS

We found a significant preponderance of high-grade tumors among men and a lower surgical cure rate in men (23%) than in women (71%). Patients resistant to medical treatment were mainly men (7/8), six of whom showed tumor progression despite postoperative medical treatment, which led to multiple therapies and eventually death in three. The median score for ERα expression was 1 in men (range, 0-8) and 8 in women (range, 0-12) (P<0.0001). The expression of ERα was inversely correlated with tumor size (r=-0.59; P<0.0001) and proliferative activity. All dopamine agonist-resistant tumors and all grade 2b (invasive and proliferative) tumors (from ten men and four women) were characterized by low ERα expression.

CONCLUSIONS

PRL tumors in men are characterized by lower ERα expression, which is related to higher tumor grades, resistance to treatment, and an overall worse prognosis.

Recovery of visual and endocrine function following transsphenoidal surgery of large nonfunctioning pituitary adenomas

A series of 35 patients with non-functioning pituitary adenomas undergoing transsphenoidal surgery is presented. In most cases, the presenting symptoms were related to the mass effect of the tumor. There was no operative mortality. Before surgery, visual field defects were documented in 21 patients (60%). After surgery, excluding 3 patients with preoperative blindness, 28% regained normal vision and 67% showed variable improvement. Preoperatively, 24 patients (69%) had abnormal pituitary function, 24 (69%) had hypogonadism, 7 (20%) adrenal insufficiency, 8 (23%) hypothyroidism and 2 (6%) panhypopituitarism. After pituitary surgery, all but one patient with normal preoperative function retained it. Of the patients with hypopituitarism, 11 (46%) had variable improvement and 13 (54%) had persistent deficits. After surgery, 4 patients (57%) with adrenal insufficiency recovered normal adrenal function, 7 patients (29%) with hypogonadism recovered gonadal function and 1 patient (13%) with hypothyroidism recovered thyroid function. Prior to surgery, the presence of a normal or slightly elevated PRL and a rise in TSH after TRH and in LH after GnRH stimulation were of value in predicting possible recovery of pituitary function after surgery. These observations suggest the presence of viable pituitary tissue in these cases and point out that, in some instances, the mechanism of hypopituitarism may be compression of the portal circulation, rather than destruction of the normal pituitary gland.

Successful gonadotrophin treatment of hypogonadism in postoperative patients with macroprolactinoma and persistent hyperprolactinaemia

We report on two males with prolactinoma in whom hyperprolactinaemia and hypogonadism persisted for several years postoperatively despite the administration of a dopamine agonist or bromocriptine. In these patients, a GnRH test revealed no response in the levels of serum LH or FSH. An hCG stimulation test provoked no response in the serum levels of testosterone. Case 1, who was 28 years old at the first visit, received parenteral testosterone and appreciable virilization of the genitalia was noted within a few months. When he married and desired to father a child, the treatment was switched to hCG/hMG combined therapy and spermatozoa appeared subsequently in the ejaculate, although their numbers were low. His wife conceived and delivered a healthy baby girl. Case 2 was a single young man who presented with hypogonadotrophic hypogonadism and hyperprolactinaemia. He was started on hCG injections three times per week and the maturation of his genitalia was advanced rapidly. Semen analyses showed sperm concentration and motility to be within the normal range. Post-treatment GnRH test revealed no improvement in gonadotrophin responses for LH or FSH. In both cases, the hCG test repeated after the gonadotrophin treatment showed normal basal and stimulated testosterone levels. During the course of gonadotrophin treatment in these cases, serum prolactin levels remained elevated, and it is suggested that, in the two cases, the hypothalamo-pituitary function was disturbed by the tumour or its manipulation and the capacity of the pituitary gland to secrete gonadotrophin was impaired. Under such circumstances with persisting hyperprolactinaemia, hCG and/or hCG/hMG combination treatment can induce normal virilization and advance spermatogenesis sufficiently to achieve fertility.

Effect of different types of textile fabric on spermatogenesis: an experimental study

The effect of different types of textile fabric on spermatogenesis was studied. Twenty-four dogs were divided into two equal groups, one of which wore cotton underpants and the other polyester ones. Seven dogs wearing nothing were used as controls. The underwear was fashioned to fit loosely in the scrotal area so as to avoid its insulating effect. It was worn continuously for 24 months during which the semen character, testicular temperature, hormones (serum testosterone, follicle stimulating hormone, luteinizing hormone, prolactin) and testicular biopsy were examined. The garment was then removed, and the same investigations repeated through another 12 months. The results were analysed statistically. In the polyester group the testicular temperature showed insignificant changes during the period when the pants were worn (P > 0.05). By the end of the 24 months there was a significant decrease in sperm count and motile sperms, with an increase in abnormal forms (P < 0.001); the testicular biopsy showed degenerative changes. After garment removal the semen character improved gradually to normal in 10 dogs; two remained oligozoospermic. There were insignificant changes (P > 0.05) in hormones during the study. In contrast, the cotton and control groups showed insignificant changes (P > 0.05) in all the aforementioned parameters during the 36 months of the study. The polyester pants thus had a deleterious effect on spermatogenesis in the dogs which was, however, reversible in the majority of cases. The cause of this effect is unknown, but it may be assumed that the electrostatic potentials generated by the polyester fabric play a role in it.

Routine endocrine screening in impotence

Routine hormonal screening (serum testosterone and prolactin) of 300 men presenting with a primary complaint of impotence resulted in detection of endocrine dysfunction in 5 men (1.7%). Four patients had hypogonadism, and 1 patient had a prolactin-secreting pituitary adenoma. The cost of screening these men for endocrine dysfunction was $34,722.00. Despite this cost and the low yield of endocrine disease detection, routine determination of serum testosterone and prolactin provides useful information to the clinician evaluating impotent men and when abnormal, indicates the need for thorough endocrine evaluation.

Circulating Levels of Immunoreactive Peptides and Steroid Hormones in Bronchogenic Carcinoma

Plasma levels of immunoreactive parathormone (iPTH), immunoreactive calcitonin (iCT) and prostaglandins (PGE2) were measured by RIA in 115 patients with bronchogenic carcinoma. In 37 of these cases the following hormones were also assayed: adrenocorticotropic hormone (ACTH), cortisol, plasma renin activity (PRA), aldosterone, prolactin, human growth hormone (HGH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH) human chorionic gonadotropin (HCG), progesterone (P), an-drostenedoone (A), testosterone (T), estradiol (E2) and dehydropiandrosterone sulphate (DHAS). High serum levels of many hormone-like substances and hormones were found and the levels of certain hormones varied in some cases according to the clinical evolution of the disease and the response to therapy.

Altered pulsatile secretion of luteinizing hormone in hypogonadal men with hyperprolactinaemia

To explore the mechanism for the hypogonadism associated with prolactin hypersecretion in men we examined luteinizing hormone (LH) secretory profiles in four hyperprolactinaemic men before and during treatment with bromocriptine. Pretreatment serum prolactin levels were increased 4-100 fold and serum testosterone levels were low in three men and low-normal in the fourth subject. Mean LH levels were low-normal and the frequency of spontaneous LH secretory episodes was less than normal in three of four men. Bromocriptine reduced serum prolactin levels to normal; subsequently, serum testosterone levels increased and libido and potency improved markedly in each man. The rise in serum testosterone levels was associated with an increase in mean LH concentrations and in LH pulse frequency. Mean follicle-stimulating hormone levels also increased during bromocriptine treatment. Insofar as each LH pulse is believed to reflect a discharge of gonadotrophin releasing hormone from the anterior hypothalamus, our data suggest that a major abnormality in hyperprolactinaemic men with hypogonadism is a disorder of the neuroregulatory mechanism for pulsatile gonadotrophin-releasing hormone secretion.

Hyperprolactinaemia in males with and without pituitary macroadenomas

To ascertain whether in hyperprolactinaemic men pituitary macroadenomas represent the end stage of a disease process wherein the only early symptom is impotence, the features of 16 hyperprolactinaemic men with radiological evidence of pituitary macroadenomas were compared with those of 10 hyperprolactinaemic men without pituitary macroadenomas. All were impotent and 25 had low serum testosterone levels. The group with pituitary macroadenoma was older (48.1 vs 63.2 years) and had tolerated impotence for longer (10.4 +/- 6.0 vs 4.5 +/- 2.1 years). 6 of them had visual field defects (none in the other group), 14 had hypopituitarism (1 in the other group), and 14 were initially seen for problems other than sexual dysfunction (whereas all 10 without pituitary macroadenomas were seen primarily for evaluation of recent onset of impotence). In the macroadenoma group bromocriptine restored serum prolactin levels in 13 of the 16 and serum testosterone and potency in 5, whereas in the non-tumour group it restored serum prolactin levels in all 10 and serum testosterone and potency in 9.