Predictors of Chronic LH-Testosterone Axis Suppression in Male Macroprolactinomas With Normoprolactinemia on Cabergoline

Recovery from hypogonadism in men with prolactinoma treated with dopamine agonists

PURPOSE

In men with prolactinoma treated with dopamine agonists (DA), the extent, timeline, and predictive factors of gonadotropic axis recovery are still unclear.

METHODS

We analyzed data of 97 men with a prolactinoma treated with DA (77/97 macroprolactinomas). We excluded patients with primary hypogonadism, surgery < 12 months after DA initiation, and patients with tumors < 5 mm or prolactin < 45 µg/l at diagnosis.

RESULTS

Among the 97 patients, 12 had normal total testosterone (NT group) and 85 had low testosterone at diagnosis (LT group). In the NT group, testosterone rose from a mean of 13.5 nmol/l to 17.1nmol/l at 6 months (n = 11; p < 0.05) then remained stable at 12 months (n = 8). In the LT group, testosterone rose from a mean of 5.2 nmol/l to 9.6 nmol/l at 6 months (n = 66; p < 0.001) and further to 13.1nmol/l at 12 months (n = 40; p < 0.001) then remained stable. Recovery from hypogonadism occurred in 43%, 50%, and 54% of patients at 6, 12 and 24 months, respectively (61%, 69 and 69% if prolactin was normal). Factors independently associated with persistent hypogonadism at 12 months were at baseline the presence of visual field deficit and lower testosterone levels, while the most significant independent predictor of persistent hypogonadism at one year was a testosterone level < 7.4 nmol/l at 6 months, with 91% sensitivity and 94% specificity.

CONCLUSION

Testosterone levels recover in a small majority of men with prolactinoma mostly during the first year of DA treatment. However, testosterone replacement could be considered earlier in patients with large and compressive tumors, and in whom testosterone remains below 7.4 nmol/l after 6 months of DA treatment.

Increase in Testosterone Levels and Improvement of Clinical Symptoms in Eugonadic men With a Prolactin-secreting Adenoma

Objective

Testosterone concentrations, albeit rarely, may be in the normal range (>3.0 ng/mL) in men with a prolactin-secreting pituitary adenoma (PSPA-nt). The evolution of total, bioavailable testosterone, gonadotropin levels, and that of graded symptoms of testosterone deficiency (TD) are uncertain in these patients.

Design

Retrospective case-control longitudinal study at a tertiary referral center.

Methods

From 287 men, we selected 25 PSPA-nt men undergoing prolactin normalization (<20.0 ng/mL) during the follow-up. Graded symptoms of TD were investigated by structured interviews. Biochemical changes and TD symptoms were compared to those of a matched cohort of 61 men with pituitary neoplasms and normal testosterone levels (PA-nt).

Results

Baseline testosterone levels were similar between PSPA-nt and PA-nt subjects. The prevalence of specific and suggestive symptoms of TD was higher in PSPA-nt (20% and 68%) than in PAnt (3.3 and 29.5%; P = .02 and P = .0015, respectively). At the follow-up, total and bioavailable testosterone levels increased in PSPA-nt but not in PA-nt patients (Δ change: 1.28 ± 2.1 vs0.03 ± 1.5 ng/mL, + 0.33 ± 0.55 vs-0.26 ± 0.60 ng/mL; P = .0028 and P = .0088, respectively). LH and FSH levels also increased in PSPA-nt men (P < .05). Specific and suggestive, but not nonspecific symptoms of TD, improved only in PSPA-nt men (P < .05 for both). Baseline testosterone and LH were the strongest predictors of testosterone improvement in PSPA-nt patients.

Conclusion

Despite having normal testosterone levels at baseline, patients with PSPA-nt experience a relief of TD symptoms and an improvement of their pituitary-gonadal axis function following prolactin normalization, especially when baseline TT and LH levels are in the low-normal range.

Prolactin-secreting pituitary adenomas: male-specific differences in pathogenesis, clinical presentation and treatment

Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents. Therefore, the management of PRLomas in men is challenging in many cases. Additionally, hyperprolactinemia is associated with a significant negative impact on men's health, including sexual function and fertility potential, bone health, cardiovascular and metabolic complications, leading to decreased quality of life. In this review, we highlight the differences in pathogenesis, clinical presentation and treatment of PRLomas concerning the male sex.

Giant prolactinoma in Asian-Indians: A single-center experience from Western India

PURPOSE

Giant prolactinomas (GP) are rare tumors accounting for 4.3% of prolactinomas, with paucity of literature from India. We aim to describe clinical, biochemical, radiological, and treatment outcomes in a large series of Asian-Indian patients with GP.

METHODS

A single-center retrospective analysis of GPs (n=84), age-based (adults: 66 versus pediatric: 18) and gender-based (males: 64 versus females: 20) comparison was done.

RESULTS

The mean age at presentation was 34.1±13years, and 64 (76.2%) were males. Males were younger at presentation (32.1±12.2 versus 40.1±13.8years, P: 0.01). The majority presented with mass-effect-related manifestations (visual disturbances: 91.6%, headache: 84.5%) and/or hypogonadism (98.7%). At baseline, largest tumor dimension was 5.3±1.0cm, and serum prolactin was 8343 (3865.5-12,306) ng/mL; most (94.6%) had gonadal axis involvement. Dopamine-agonist (DA) as first-line therapy (45/67, 67.2%) achieved normoprolactinemia (maximum cabergoline dose: 2.0±1.2mg/week) in 36/45 (80%) and tumor response (≥50% reduction) in 36/37 (97.3%) patients at the last follow-up (median duration: 33 [14.5-53.5]months). Notably, gonadal axis recovery was poor (6/30, 20%) despite normoprolactinemia post-DA monotherapy. At latest follow-up, secondary hypothyroidism (32.5% versus 82.6%, P: 0.001) and central hypocortisolism (5.6% versus 42.9%, P: 0.007) were less frequent in DA monotherapy (n=43) than in multimodal therapy group (n=23). The proportion of males (94.4% versus 71.2%, P: 0.04) was higher in the pediatric age group, with DA-induced (first-line) normoprolactinemia observed in 66.7% of them.

CONCLUSION

GP has male predominance, DA as first-line therapy normalized prolactin in four-fifths of patients with better preservation of HPT and HPA axes in patients with DA monotherapy.

Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement

This Consensus Statement from an international, multidisciplinary workshop sponsored by the Pituitary Society offers evidence-based graded consensus recommendations and key summary points for clinical practice on the diagnosis and management of prolactinomas. Epidemiology and pathogenesis, clinical presentation of disordered pituitary hormone secretion, assessment of hyperprolactinaemia and biochemical evaluation, optimal use of imaging strategies and disease-related complications are addressed. In-depth discussions present the latest evidence on treatment of prolactinoma, including efficacy, adverse effects and options for withdrawal of dopamine agonist therapy, as well as indications for surgery, preoperative medical therapy and radiation therapy. Management of prolactinoma in special situations is discussed, including cystic lesions, mixed growth hormone-secreting and prolactin-secreting adenomas and giant and aggressive prolactinomas. Furthermore, considerations for pregnancy and fertility are outlined, as well as management of prolactinomas in children and adolescents, patients with an underlying psychiatric disorder, postmenopausal women, transgender individuals and patients with chronic kidney disease. The workshop concluded that, although treatment resistance is rare, there is a need for additional therapeutic options to address clinical challenges in treating these patients and a need to facilitate international registries to enable risk stratification and optimization of therapeutic strategies.

Case Report: Multiple prolactinomas in a young man with Kallmann syndrome and familial hypocalciuric hypercalcemia

Introduction

The occurrence of prolactinomas in sex hormone treated patients with central hypogonadism is extremely rare.

Case presentation

We present a Caucasian male patient who was diagnosed with Kallmann syndrome (KS) at age 15 years. Testosterone treatment was started. At age 26 the patient presented with mild headache. MRI revealed two separate pituitary adenomas along with the absence of the olfactory bulbs. Given the presence of marked hyperprolactinemia (17x upper limit of the reference range) the diagnosis prolactinoma was made and treatment with cabergoline was started which resulted in a complete biochemical response and in marked reduction of both adenomas in size. Hypogonadism persisted and testosterone replacement therapy was continued. Genetic testing of genes associated with pituitary tumors, Kallmann syndrome and idiopathic hypogonadotropic hypogonadism was negative. Mild concomitant hypercalcemia in accordance with familial hypocalciuric hypercalcemia (FHH) prompted mutation analysis of the calcium receptor (CASR) gene which yielded a pathogenic inactivating variant.

Discussion/conclusion

The presence of two separate prolactinomas in a patient with KS has not yet been reported in the literature. The effect of sex hormone treatment of KS patients on the possible development of prolactinoma is unknown at present. The occurance of multiple prolactinomas in our patient suggests increased susceptibility. Although CaSR is expressed in GnRH neurons in mouse brain and CaSR deficient mice have a reduced hypothalamic GnRH neuronal population, the relevance of the CASR gene variant in our patient for the KS phenotype is unclear at present.

Giant prolactinoma in children and adolescents: a single-center experience and systematic review

PURPOSE

Giant prolactinoma (GP) in childhood and adolescence is a rare entity with scarce literature. We aimed to describe clinical features, biochemistry, radiology, genetics, management, and outcome in pediatric (≤ 20 years) GP.

METHODS

Retrospective record review of 18 pediatric GP patients from our center and systematic review including these and 77 from the literature (total cohort: 95).

RESULTS

GP constituted 20% of our pediatric prolactinoma cohort. In the total cohort (age: 15.4 ± 3.5 years), the majority (77, 82.8%) were males. Mass effect symptoms (88.6%), and pubertal delay/arrest in males (82.1%) were frequent. Median basal prolactin was 8649 (3246-17,532) ng/ml and the maximum tumor dimension was 5.5 ± 1.5 cm. MEN1 and AIP mutations were noted in 7 (21.9%) and 6 (18.8%) patients, respectively. Males with central hypogonadism had baseline bi-testicular volume of 20.2 ± 8.4 cc, lower LH than FSH (-2.04 ± 0.9 vs. -0.7 ± 1.6 SDS, p = 0.0075), and mostly, normal inhibin B. Majority (49/76, 64.5%) received dopamine agonist (DA) as first-line treatment with additional therapy in 35% (17/49). DA monotherapy arm had less frequent central hypothyroidism (42.9% vs 87.1%, p = 0.002) and central adrenal insufficiency (7.1% vs 66.7%, p = 0.0003) than multimodal therapy. A smaller tumor dimension (4.7 vs. 5.7 cm, p = 0.04) was associated with normoprolactinemia on DA monotherapy and AIP mutations (33.3% vs. nil, p = 0.02) with multimodal therapy.

CONCLUSION

GP is characterized by male predominance with frequent delay/arrest of puberty (82%), but relative sparing of the FSH-inhibin B axis in boys. DA monotherapy may be preferred as the first-line therapy in pediatric GP.

Predicting hypogonadotropic hypogonadism persistence in male macroprolactinoma

PURPOSE

To study the baseline characteristics predicting hypogonadotropic hypogonadism (HH) persistence in men with macroprolactinoma that achieved prolactin normalization.

DESIGN

Retrospective cohort study.

METHODS

Male patients diagnosed with macroprolactinoma and HH that received cabergoline treatment with subsequent prolactin normalization were included: men that achieved eugonadism, and men that remained hypogonadal. Patient's demographic, clinical and biochemical parameters, sellar imaging, and visual fields tests were obtained. Univariate and multivariate models were used to identify predictors of HH persistence.

RESULTS

Fifty-eight male patients (age 49.2 ± 12.6 years) with a median baseline prolactin of 1154 ng/mL (IQR 478-2763 ng/mL) and adenoma (maximal) diameter of 25.9 ± 14.8 mm were followed for a median of 5.6 years (IQR 3.0-10.7). Twelve men (21%) suffered from HH persistence at the end of follow-up and 46 men achieved eugonadism. Forty-two out of 46 men (91%) accomplished eugonadism within the first year following prolactin normalization. In a multivariate logistic regression model, hypopituitarism (OR 10.1; 95% CI 1.10-101.94), visual field defect (OR 9.9; 95% CI 1.07-92.33), and low baseline testosterone levels (OR 0.5; 95% CI 0.29-0.93) were independent predictors of HH persistence.

CONCLUSION

In our cohort of men with macroprolactinoma that reached prolactin normalization with cabergoline treatment, 21% had HH persistence. Pituitary hormone deficiency, visual field defects, and low baseline testosterone levels were independently associated with HH persistence. 91% of men achieved eugonadism within the first year following prolactin normalization. These findings may support informed clinical decision-making regarding the initiation of testosterone replacement in men with macroprolactinomas.

Proportion and predictors of Hypogonadism Recovery in Men with Macroprolactinomas treated with dopamine agonists

INTRODUCTION

Hypogonadism is the most common form of hypopituitarism in men with macroprolactinoma. However, evidence on factors related to hypogonadism recovery is limited.

OBJECTIVES

We estimated the proportion of hypogonadism in men with macroprolactinoma exclusively treated with dopamine agonists, and we assessed the factors predicting hypogonadism recovery.

PATIENTS AND METHODS

This was a multicenter retrospective study of men with macroprolactinoma identified using ICD 9 and 10 codes and treated between 2009 and 2019 in five centers in the United Arab Emirates and Saudi Arabia. We evaluated hypogonadism, defined as low total testosterone (TT) level with normal or low gonadotropins on presentation and during the last clinic visit.

RESULTS

A total of 79 patients (median age 32 years) were included in the study. The most common symptoms at presentation were headache (73.7%), erectile dysfunction (55.4%), and low libido (54.3%). The median tumor size was 2.9 cm (1.0-9.7) at diagnosis. Sixty-three patients (79.7%) had hypogonadism at baseline. Growth hormone deficiency (GHD) and hypothyroidism were present in 34.4% and 32.9% of patients, respectively. The median serum prolactin (PRL) level was 20,175 (min-max 2254 - 500,000) mIU/l with a median serum TT of 4.5 (min-max 0.4-28.2) nmol/l. Most patients were treated with cabergoline (n = 77, 97.5%) with a median of 6 (min-max 0.6-22) years. At follow-up, 65% of patients recovered their pituitary-testicular axis. Patients with recovered hypogonadism had smaller median tumor size (2.4 [1-5.4] vs. 4.3 [1.6-9.7], p = 0.003), lower PRL level (18, 277 [2254 - 274, 250] vs. 63,703 [ 3,365-500,000], p = 0.008 ), higher TT level (4.6 [0.6-9.2] vs. 2.3 [0.5-7.3], p = 0.008), lower PRL normalization time on medical therapy (8 months (0.7-72) vs. 24 (3-120), p = 0.009) as well as lower frequency of GHD (17.1% vs. 60%, p = 0.006) and secondary hypothyroidism (17.9% vs. 57.1%, p = 0.003) compared with those with persistent hypogonadism respectively. Age at diagnosis, presenting symptoms and duration of medical therapy did not predict hypogonadism recovery.

CONCLUSIONS

About two-thirds of men with macroprolactinoma recover from hypogonadism, mostly with 24 months of therapy. Smaller adenoma size, lower prolactin level, earlier prolactin normalization, and higher testosterone patients were related to testosterone normalization.

Hypogonadism in Male Patients with Pituitary Adenoma and Its Related Mechanism: A Review of Literature

Maintaining normal gonadal axis hormone levels is important for improving the condition of male patients with pituitary adenoma. The current literature is somewhat divided on the results of evaluations of gonadal axis function in male patients with pituitary adenoma before and after treatment, and the increasing demand for better quality of life has provided motivation for this research to continue. In this article, we summarize the feasibility of using testosterone as an indicator for assessing male function and discuss the changes reported in various studies for gonadal hormones before and after treatment in male patients with pituitary adenoma. It is important for clinicians to understand the advantages of each treatment option and the effectiveness of assessing gonadal function. The rationale behind the theory that pituitary adenomas affect gonadal function and the criteria for evaluating pituitary–gonadal axis hormones should be explored in more depth.

Italian Association of Clinical Endocrinologists (AME) and International Chapter of Clinical Endocrinology (ICCE). Position statement for clinical practice: prolactin-secreting tumors

Prolactinomas are the most frequent pituitary adenomas. Prolactinoma may occur in different clinical settings and always require an individually tailored approach. This is the reason why a panel of Italian neuroendocrine experts was charged with the task to provide indications for the diagnostic and therapeutic approaches that can be easily applied in different contexts. The document provides 15 recommendations for diagnosis and 54 recommendations for treatment, issued according to the GRADE system. The level of agreement among panel members was formally evaluated by RAND-UCLA methodology. In the last century, prolactinomas represented the paradigm of pituitary tumors for which the development of highly effective drugs obtained the best results, allowing to avoid neurosurgery in most cases. The impressive improvement of neurosurgical endoscopic techniques allows a far better definition of the tumoral tissue during surgery and the remission of endocrine symptoms in many patients with pituitary tumors. Consequently, this refinement of neurosurgery is changing the therapeutic strategy in prolactinomas, allowing the definitive cure of some patients with permanent discontinuation of medical therapy.

Optimal testosterone level to improve symptoms of hypogonadism without causing dopa-testotoxicosis in male macroprolactinoma

BACKGROUND

Male prolactinoma treatment by dopamine agonists (DA) restores sexual function. However, excessive DA dose can lead to impulse control disorder.

OBJECTIVES

The aim of this retrospective study was to determine the level of testosterone that eliminates symptoms and provides fertility in male macroprolactinoma, without causing these adverse effects.

MATERIALS AND METHODS

Twenty-seven male patients with macroprolactinoma were included. There were 16 macro (≥1-2.8 cm), 7 large macro (≥2.9-3.9 cm) and 4 giant (≥4 cm) adenomas. Prolactin (PRL) and testosterone (T) levels were evaluated. A timeline was created to analyze improvement in symptoms of hypogonadism and infertility. Testosterone levels were compared with age-matched controls.

RESULTS

Mean PRL, basal tumor diameter and shrinkage were 2,846±3,415 ng/mL, 27.2±10.2 mm and 63.4%, respectively. Basal T levels were 1.6±1.0 ng/mL for patients and 4.4±1.5 ng/mL for controls (p<0.001). Mean T level in the asymptomatic period was significantly lower than in controls (3.2±0.4 ng/mL vs. 4.4±1.5 ng/mL, respectively; p=0.002), while mean PRL was 27.2 ng/ml. Fertility was achieved in 6 of the patients seeking fertility, and there was no difference in T level between these patients and controls (3.7±0.8 ng/mL and 4.4±1.5 ng/mL, respectively; p=0.14); when fertility was achieved, mean PRL was 26.9±23 ng/mL.

CONCLUSION

Patients should be carefully questioned regarding complaints at each consultation, and DA dose should not be increased unnecessarily, to avoid possible serious adverse effects.