Treatment of hyperprolactinemia: a systematic review and meta-analysis

Prolactinomas: Preconception and During Pregnancy

Prolactinomas are a common cause of infertility in women. Medical treatment with dopamine agonists (DAs) has an excellent efficacy at restoring fertility and a reassuring safety profile in early pregnancy. Surgical treatment before conception is required in some cases of large macroadenomas and incomplete treatment response. In women with microprolactinomas, the pregnancy course is usually uneventful. In women with macroprolactinomas that are near/abut the optic chiasm, symptomatic tumor enlargement can occur during pregnancy and require a multidisciplinary team approach. This review provides an update regarding outcomes and management of prolactinomas before conception, during pregnancy, and postpartum.

A Comprehensive Review of the Efficacy and Safety of Dopamine Agonists for Women with Endometriosis-associated Infertility from Inception to July 31, 2022

Background

Current medical management of endometriosis leads to suppression of ovulation and will not be helpful for women with endometriosis who are desirous of pregnancy. Thus, drugs that can both treat endometriosis and its associated infertility are highly warranted.

Objective

Anti-angiogenic agents are potential drugs for patients with endometriosis and infertility. Among these drugs, dopamine agonist (DA) is promising since it does not interfere with ovulation, is safe, and not teratogenic. The aim of the study is to determine the efficacy and safety of DA for improving reproductive outcomes in women with endometriosis and infertility.

Methods

A qualitative narrative review was done from inception to July 31, 2022 using the appropriate MeSH terms in PubMed, Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, ClinicalTrial.gov, and World Health Organization International Clinical Trials Registry Platform. Date analysis was through qualitative analysis and synthesis of researches and their outcome measures.

Results

No studies used the core outcomes for trials evaluating treatments for infertility associated with endometriosis. All the included articles in the review supported the possible anti-angiogenic effects of DA on the vascular endothelial growth factor [VEGF] /VEGF receptor system. The use of DA does not have an effect on ovulation and menstrual cyclicity. Studies on safety profile of DA were consistent with existing data.

Conclusion

Most of studies reviewed demonstrated that DA were effective in reducing endometriotic lesions. However, further research is required to establish whether this anti-angiogenic effect can improve reproductive outcomes in women with endometriosis-associated infertility.

Quality of life in Prolactinoma: A systematic review

BACKGROUND

Prolactinomas are common tumours that significantly reduce quality-of-life (QOL) due to sellar mass effect, secondary hypogonadism, and the peripheral effects of prolactin. Understanding the factors that influence QOL would provide insights into therapeutic targets to optimise patient outcomes and improve wellbeing in prolactinoma.

METHODS

A systematic review was performed in accordance with the PRISMA statement. Studies that reported patient QoL using validated metrics were included. Bias and methodological rigour were assessed using the MINORS criteria.

RESULTS

A total of 18 studies were identified studies were available for review, comprising 877 patients. Most were small cross-sectional studies at high risk of bias. Prolactinoma exhibit worse QOL than healthy controls, particularly mental and psychosocial wellbeing. QOL is also worse than patients with non-functional adenomas, but better than those with Cushing's disease and acromegaly. QOL correlates with prolactin levels, and approaches population baseline with prolonged biochemical control. Dopamine agonists and surgery both improve overall QOL, however improvements are more rapid with surgery.

CONCLUSION

Poor quality of life in prolactinoma is multifactorial, related to biochemical control, side effects of therapy, and sellar mass effect. Targeting persistent symptoms, reducing healthcare costs, and reducing side-effects of therapy are avenues to improving QOL in patients with prolactinoma.

Effects of cabergoline and dimethylcabergoline on the sexual behavior of male rats

RATIONALE

Cabergoline (CAB) is an ergot derivative typically prescribed for the treatment of hyperprolactinemia. It suppresses the release of prolactin through agonist actions on dopamine (DA) D2 receptors; however, it possesses binding affinity for other DA and 5-HT receptors. Side effects that exacerbate valvular heart disease can occur with high doses.

OBJECTIVE

The present study examined the acute, subchronic, and chronic dose-response effects of CAB and a derivative dimethylcabergoline (DMC) which acts as an antagonist instead of agonist at 5-HT 2B receptors, on appetitive and consummatory sexual behaviors of male rats.

METHODS

CAB (0, 0.03, 0.15, or 0.3 mg/kg/ml) was administered daily to sexually experienced male rats (N = 10/dose) by oral gavage for a total of 68 days. Sexual behavior was tested every 4 days during this period for a total of 16 trials. On the 17th trial, rats were administered their dose of CAB, and 4 h after were overdosed with sodium pentobarbital, perfused intracardially, and their brains processed for Fos immunohistochemistry. DMC (0, 0.03, 0.15, 0.3 mg/kg/ml) was administered daily to sexually experienced male rats (N = 10/dose) by oral gavage for a total of 36 days. Sexual behavior was tested every 4 days for a total of 9 trials.

RESULTS

CAB increased anticipatory level changes, intromissions, and ejaculations significantly across all timepoints, with the medium and high doses being most potent. The medium and high doses also increased Fos protein significantly within the medial preoptic area, whereas in the nucleus accumbens shell, the low and medium doses decreased Fos protein but the high dose increased it significantly from control. Similar to CAB, the medium and high doses of DMC increased the number of ejaculations significantly. Rats in all drug dose groups appeared healthy for the duration of the experiments.

CONCLUSIONS

Both CAB and DMC facilitate ejaculations, and CAB further facilitates measures of anticipatory sexual motivation and intromissions. These data suggest that both could be used as treatments for sexual arousal disorders and ejaculation/orgasm disorders with little or no untoward side effects at low doses.

Mechanisms of adverse mammary effect induced by olanzapine and therapeutic interventions in rat model

BACKGROUND

Olanzapine antagonizes dopamine receptors and is prescribed to treat multiple psychiatric conditions. The main side effect of concern for olanzapine is weight gain and metabolic syndrome. Olanzapine induces hyperprolactinemia, however its effect on the mammary gland is poorly documented.

METHODS

Rats received olanzapine by gavage or in drinking water at 1, 3, and 6 mg/kg/day for 5-40 days or 100 days, with and without coadministration of bromocriptine or aripiprazole and using once daily or continuous administration strategies. Histomorphology of the mammary gland, concentrations of prolactin, estradiol, progesterone, and olanzapine in serum, mammary gland and adipose tissue, and mRNA and protein expressions of prolactin receptors were analyzed.

RESULTS

In adult and prepubescent female rats and male rats, olanzapine induced significant development of mammary glands in dose- and time-dependent manners, with histopathological hyperplasia of mammary ducts and alveoli with lumen dilation and secretion, marked increase of mammary prolactin receptor expression, a marker of breast tissue, and with mild increase of circulating prolactin. This side effect can be reversed after medication withdrawal, but long-term olanzapine treatment for 100 days implicated tumorigenic potentials indicated by usual ductal epithelial hyperplasia. Olanzapine induced mammary development was prevented with the coaddition of the dopamine agonist bromocriptine or partial agonist aripiprazole, or by continuous administration of medication instead of a once daily regimen.

CONCLUSIONS

These results shed light on the previously overlooked effect of olanzapine on mammary development and present experimental evidence to support current clinical management strategies of antipsychotic induced side effects in the breast.

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.

Cabergoline treatment for surgery-naïve non-functioning pituitary macroadenomas

PURPOSE

The treatment strategy of non-functioning pituitary adenomas (NFPAs) includes surgery, radiotherapy, medical therapy, or observation without intervention. Cabergoline, a dopaminergic agonist, was suggested for the treatment of NFPA remnants after trans-sphenoidal surgery. This study investigates the efficacy of cabergoline in surgery-naive patients with NFPA.

METHODS

Retrospective cohort study including surgery-naive patients with NFPA ≥ 10 mm, treated with cabergoline at a dose of ≥ 1 mg/week for at least 24 months. Patients with chiasmal damage were excluded. Data collected included symptoms, in particular visual disturbances, hormonal levels, tumor characteristics and size evaluated by MRI. Tumor growth was defined as an increase in maximal diameter of ≥  2 mm, and shrinkage as reduction of ≥ 2 mm.

RESULTS

Our cohort included 25 patients treated with cabergoline as primary therapy. Mean age was 63.3 ± 17.3 years, 56% (14/25) were males. Mean tumor size at diagnosis was 18.6 ± 6.3 mm (median 17 mm, range 10-36), and the average follow-up period with cabergoline was 4.6 ± 3.4 years. Out of the 25 tumors, five tumors (20%) decreased in size (mean decrease of 5.0 ± 3.0 mm), 12 tumors (48%) remained stable, and eight (32%) increased in size (mean growth of 5.0 ± 3.3 mm) with cabergoline treatment. During the first two years of cabergoline treatment, the median tumor size exhibited a reduction of 0.5 mm. Patients with an increase in tumor size had larger adenomas at diagnosis and a longer follow-up. Two patients (8%) underwent surgery due to tumor enlargement.

CONCLUSION

Primary treatment with cabergoline is a reasonable approach for selected patients with NFPAs without visual threat.

Stem Cells and Infertility: A Review of Clinical Applications and Legal Frameworks

Infertility is a condition defined by the failure to establish a clinical pregnancy after 12 months of regular, unprotected sexual intercourse or due to an impairment of a person's capacity to reproduce either as an individual or with their partner. The authors have set out to succinctly investigate, explore, and assess infertility treatments, harnessing the potential of stem cells to effectively and safely treat infertility; in addition, this paper will present the legal and regulatory complexities at the heart of stem cell research, with an overview of the legislative state of affairs in six major European countries. For couples who cannot benefit from assisted reproductive technologies (ART) to treat their infertility, stem-cells-based approaches have been shown to be a highly promising approach. Nonetheless, lingering ethical and immunological uncertainties require more conclusive findings and data before such treatment avenues can become mainstream and be applied on a large scale. The isolation of human embryonic stem cells (ESCs) is ethically controversial, since their collection involves the destruction of human embryonic tissue. Overall, stem cell research has resulted in important new breakthroughs in the treatment of infertility. The effort to untangle the complex web of ethical and legal issues associated with such therapeutic approaches will have to rely on evidence-based, broadly shared standards, guidelines, and best practices to make sure that the procreative rights of patients can be effectively reconciled with the core values at the heart of medical ethics.

Pediatric pituitary neuroendocrine tumors-a 13-year experience in a tertiary center

Introduction

Pediatric pituitary neuroendocrine tumor is a rare condition, and despite previous research focusing on this specific group, the main factors influencing the surgical cure rate have not been identified.

Methods

We conducted a single-center retrospective study on pediatric pituitary neuroendocrine tumor patients who visited Peking Union Medical College Hospital between 2010 and 2023. We collected data on their clinical characteristics, imaging features, surgical outcomes, and follow-up information. Additionally, we used multiple-factor logistic regression to investigate the factors affecting the surgical cure rate of pediatric pituitary neuroendocrine tumor.

Results

232 patients were diagnosed with pediatric pituitary neuroendocrine tumors, with a higher incidence in females. The most common type was ACTH-secreting adenoma (90/232), followed by prolactin-secreting adenoma (63/232), and growth hormone-secreting adenoma (41/232). The majority of pediatric adenomas were macroadenomas (139/232), and some tumors were associated with cystic changes or hemorrhage (58/232), while a few exhibited invasion of the cavernous sinus (33/232). The results of the multivariate analysis indicated that the different hormone secretion types, macroadenoma or the presence of cystic changes or hemorrhage were not significant risk factors for the cure rate after the first surgery. However, the invasion of the cavernous sinus was found to be an important factor influencing the postoperative cure rate. Most pediatric pituitary neuroendocrine tumors with cavernous sinus invasion were macroadenomas, and some displayed characteristics of refractory pituitary neuroendocrine tumors, with some patients experiencing irreversible complications after surgery.

Conclusion

Pediatric pituitary neuroendocrine tumors are complex, and the postoperative cure rate is particularly poor for tumors with cavernous sinus invasion. Although macroadenoma itself does not significantly impact the postoperative cure rate, it is still recommended to diagnose and treat early to avoid unnecessary surgery or surgical complications.

Pituitary adenomas registry in Thailand

PURPOSE

Pituitary adenomas are the most common sellar tumors, and may cause adverse outcomes in terms of morbidity and mortality if left untreated or if diagnosis is delayed. No data exists on the prevalence, characteristics, and prognosis of pituitary adenomas in Thailand. The systematic registration of clinical characteristics may improve patient care and prognosis for this disease in Thailand.

METHODS

This was a retrospective study conducted in 11 academic referral centers. All patients diagnosed with pituitary adenomas during the 2011---2014 period were enrolled in the study. The information was correlated with two national databases.

RESULTS

A total of 1,283 pituitary adenoma patients were identified. The adenomas were: non-functioning 50.1%, prolactinoma 29.4%, acromegaly 14.7%, Cushing disease 3.8%, gonadotropin-producing tumor 1.0%, TSH-secreting tumor 0.6%. The mean age was 49.2±15.2 years. Sixty-three percent of patients were female. Most common complaint was visual impairment (27.7%). The average size of the tumor was 22.2±16.1 mm. Fifty-nine percent of patients underwent surgery. Median follow-up was 27.4 months (0-24 years). After treatment, 72.4% improved, and 10.4% were cured. Overall results of treatment in non-functioning adenoma, prolactinoma (medically treated), acromegaly, Cushing, TSH, gonadotropin producing adenoma were: improved/cured in 81/5.5, 86/5.7, 55.9/30, 54.2/31.2, 85.7/14.3, 69.2/15.4% respectively.

CONCLUSION

Pituitary adenomas in academic centers in Thailand were found predominantly in female in the 4th decade of life. After treatment 72.4% of patients improved and 10% had full recovery. A health promotion system aimed to improve patient and physician recognition and physician expertise may improve the prognosis of these diseases.

Primary takotsubo syndrome with recurrent prolactinoma

Both peripartum cardiomyopathy (PPCM) and takotsubo syndrome (TTS) are diagnoses of exclusion and are thus considered a heterogeneous disease group. TTS is generally triggered by psychogenic or physical stress. Recently, the anti-angiogenic factor cleaved prolactin has been noted as a cause of PPCM, but the precise mechanisms of these diseases remain unexplained. An 87-year-old female with a past surgical history, including transsphenoidal endoscopic surgery to remove a pituitary prolactinoma, recently underwent surgery to repair a left-sided femoral neck fracture and developed dyspnea followed by back pain; shortly after, she became embarrassed by fecal incontinence. Her initial electrocardiogram showed T wave inversions with QT prolongation leading to sustained ventricular tachycardia. No obstructive coronary artery disease was found on emergent coronary angiography, and the left ventriculography findings were consistent with TTS. After acute-phase treatment, she was diagnosed with recurrent prolactinoma based on her head magnetic resonance imaging findings. This patient's high levels of prolactin may have played a role in the pathogenesis of TTS.

Learning objective

Peripartum cardiomyopathy and takotsubo syndrome (TTS) are diagnosed by exclusion, and their precise mechanisms remain unknown. We present a case of TTS associated with a prolactinoma.

Diagnosis and Management of Pituitary Adenomas: A Review

Importance

Pituitary adenomas are neoplasms of the pituitary adenohypophyseal cell lineage and include functioning tumors, characterized by the secretion of pituitary hormones, and nonfunctioning tumors. Clinically evident pituitary adenomas occur in approximately 1 in 1100 persons.

Observations

Pituitary adenomas are classified as either macroadenomas (≥10 mm) (48% of tumors) or microadenomas (<10 mm). Macroadenomas may cause mass effect, such as visual field defects, headache, and/or hypopituitarism, which occur in about 18% to 78%, 17% to 75%, and 34% to 89% of patients, respectively. Thirty percent of pituitary adenomas are nonfunctioning adenomas, which do not produce hormones. Functioning tumors are those that produce an excess of normally produced hormones and include prolactinomas, somatotropinomas, corticotropinomas, and thyrotropinomas, which produce prolactin, growth hormone, corticotropin, and thyrotropin, respectively. Approximately 53% of pituitary adenomas are prolactinomas, which can cause hypogonadism, infertility, and/or galactorrhea. Twelve percent are somatotropinomas, which cause acromegaly in adults and gigantism in children, and 4% are corticotropinomas, which secrete corticotropin autonomously, resulting in hypercortisolemia and Cushing disease. All patients with pituitary tumors require endocrine evaluation for hormone hypersecretion. Patients with macroadenomas additionally require evaluation for hypopituitarism, and patients with tumors compressing the optic chiasm should be referred to an ophthalmologist for formal visual field testing. For those requiring treatment, first-line therapy is usually transsphenoidal pituitary surgery, except for prolactinomas, for which medical therapy, either bromocriptine or cabergoline, is usually first line.

Conclusions and Relevance

Clinically manifest pituitary adenomas affect approximately 1 in 1100 people and can be complicated by syndromes of hormone excess as well as visual field defects and hypopituitarism from mass effect in larger tumors. First-line therapy for prolactinomas consists of bromocriptine or cabergoline, and transsphenoidal pituitary surgery is first-line therapy for other pituitary adenomas requiring treatment.

Withdrawal of dopamine agonist treatment in patients with hyperprolactinaemia: A systematic review and meta-analysis

OBJECTIVE

To estimate the proportion of patients with persistent normoprolactinaemia following dopamine agonist (DA) withdrawal and to identify predictors of successful withdrawal in patients with hyperprolactinaemia.

DESIGN, PATIENTS, AND MEASUREMENTS

A systematic review of observational eligible studies were identified by searching PubMed and Embase. The primary outcome was the proportion of patients with normoprolactinaemia after cessation of DA treatment. Secondary outcome included the proportion of patients with normoprolactinaemia after DA withdrawal using individual patient data. Risk of bias was assessed by using Newcastle-Ottawa Scale. Pooled proportions were estimated using a random effects model in case I²  ≤ 75% or by reporting range of effects if I²  > 75%.

RESULTS

Thirty-two observational studies enroling 1563 patients were included. The proportion of patients with persistent normoprolactinaemia ranged from 0% to 75% (I²  = 84%). Heterogeneity was partly explained by age with more successful withdrawal in patients of higher age. Individual patient data analyses suggested that the proportion of patients with persistent normoprolactinaemia 6 months after DA withdrawal with a low maintenance dose and full regression of the prolactinoma was 87.7% (95% confidence interval [CI] = 60.7-97.1; I²  = 0%) and 58.4% (95% CI = 23.8-86.3; I²  = 75%) for microadenomas and macroadenomas, respectively.

CONCLUSIONS

The proportion of patients with persistent normoprolactinaemia following DA withdrawal treatment varied greatly, partly explained by the mean age of participants of the individual studies. Individual patient data analysis suggested that successful withdrawal was likely in patients with full regression of prolactinomas using a low maintenance dose before cessation.

Experience with Dopamine Agonists in the Treatment of Prolactinomas

The article is devoted to the conservative treatment of hyperprolactinemia of tumor origin. Cabergoline is considered as an effective treatment not only for microadenomas but also for large pituitary tumors which is illustrated by the clinical case of the patient P. The most important effects of cabergoline demonstrated in this clinical case are reduction in the size of the adenoma from macro to micro, reverse development of chiasmal syndrome with restoration of visual functions, achievement and maintenance of the target level of prolactin. Besides the article focused on the possible development of primary and secondary resistance to dopamine analogues. One of such difficult clinical scenarios is illustrated by the clinical case of patient M., who was treated with different dopamine analogues with the development of secondary dopamine resistance. Along with described in literature possible mechanisms for its development in our patient we also suggest the role of prolonged inadequate therapy with dopamine agonists, when the dose of the drug was not properly adjusted, despite not reaching the target prolactin level. The literature considers several ways of optimization of treatment in resistant patients but despite of this fact it remains one of unresolved problems in the management of patients with hyperprolactinemia.

Efficacy of cabergoline therapy in patients with non-functioning pituitary adenomas: A single center clinical experience

Introduction

To evaluate the response to cabergoline (CBG) treatment in patients with non-functioning pituitary adenomas (NFPA).

Subjects and methods

Retrospective, single tertiary care center study. A total of 44 patients were treated with 3 mg/week of CBG, 32 after surgical treatment (transsphenoidal surgery [TSS] in 27 and TC in 5 patients) and 12 as primary therapy. Mean age was 59.2 ± 12 years and 23 (52.2%) were women. Response to therapy was ascertained by serial magnetic resonance imaging. The median duration of CBG therapy was 30 months (IQR 24-48). Response to CBG therapy was defined as a greater than 20% reduction in tumor size and volume.

Results

A significant reduction in tumor size was documented in 29 patients (66%), whereas in 11 patients (25%) the tumor increased in size and in 4 (9%), it remained stable. Significant tumor shrinkage was documented in 4 (33.3%) of 12 patients treated primarily and in 23 (71.8%) of those treated secondarily. The three-year progression-free survival was 0.61.

Conclusion

Cabergoline therapy is effective in reducing tumor growth in over two thirds of patients with NFPA, however 16% of patients will escape to this beneficial effect and will require alternative forms of treatment to halt tumor progression.

Serum prolactin level to tumor size ratio as a potential parameter for preoperative differentiation of prolactinomas from hyperprolactinemia-causing non-functional pituitary adenomas

OBJECTIVE

Preoperative diagnosis of prolactinomas is critical because dopamine agonists have been regarded as a primary treatment. However, serum prolactin level alone is suboptimal for differentiating prolactinomas from hyperprolactinemia-causing non-functioning pituitary adenomas (NFPAs). By using the tumor size, the authors tried to investigate an effective parameter for the discrimination.

METHODS

We performed a retrospective review of patients who underwent trans-sphenoidal surgery for pituitary lesions in a single institute between January 2015 and May 2021. Using the receiver operating curve (ROC) analyses, we compared performances of serum prolactin levels (PRL), a ratio of serum PRL levels to maximal tumor diameter (MD) (PRL/MD; PDR1), and MD squared (PRL/[MD]²; PDR2) in preoperative diagnosis of prolactinomas.

RESULTS

223 patients with NFPAs (n=175) and prolactinomas (n=48) were included in the analysis. A moderate correlation was found between serum prolactin levels and MDs in prolactinomas (pearson's r_prl=0.43, p=0.002), whereas a weak correlation was observed in NFPAs (pearson's r_nfpa=0.17, p=0.028). Among diagnostic parameters, PDR2 exhibited the optimal diagnostic performance with the cutoff value of 0.83 [㎍/L]/mm² (area under the curve [AUC] = 0.945), compared to the PDR1 (8.93 [㎍/L]/mm with AUC 0.938) and PRL (99.4 ㎍/L with AUC 0.910). In the external validation study, PDR2 maintained superior performance over PDR1 and PRL (Accuracy of 94.8%, 91.8%, and 75.8%, respectively).

CONCLUSIONS

PDR2 was a more effective indicator than prolactin alone in the preoperative differential diagnosis of prolactinomas and NFPAs, which may help select patients who need medical treatment first.

Treatment of hyperprolactinemia: A single-institute experience

BACKGROUND

Dopamine agonists such as bromocriptine and cabergoline have been found to be an effective treatment for hyperprolactinemia, not only inducing adenoma shrinkage but also lowering serum prolactin levels. Among known dopamine agonists, cabergoline is the drug of choice due to its enhanced tolerability compared with bromocriptine. This study aimed to evaluate cabergoline's effectiveness, along with transsphenoidal surgery, in the treatment of hyperprolactinemia.

METHODS

We retrieved all patients with a diagnosis of prolactinoma who were treated in our hospital during 2000-2018. A total of 208 patients were enrolled in the analysis after applying exclusion criteria. Patients were divided into four groups according to the treatments received. The demographic data, dosage and duration of cabergoline, and serum prolactin levels at different time points were collected for analysis.

RESULTS

Normalization was achieved in 59 patients (83.10%) within a short median duration of 2.80 months among those treated with cabergoline only. Although cabergoline alone was effective and well-tolerated, our data showed that long-term remission rates were more favorable when surgery was involved. The long-term remission rate of all patients enrolled was 53.8% (112 patients among 208 patients). The long-term remission rates for the different treatment groups were 17.8% (8 of 45 patients) in Group 1 (Operation→Drug), 83.3% (5 of 6 patients) in Group 2 (Drug→Operation), 79.0% (68 of 86 patients) in Group 3 (Operation only), and 43.7% (31 of 71 patients) in Group 4 (Drug only).

CONCLUSION

Cabergoline has been demonstrated to be effective and should be considered as a first-line treatment for hyperprolactinemia. In our study, transsphenoidal surgery was also demonstrated to achieve good results compared with medical treatment. Surgical intervention may resurface as an alternative first-line treatment. When used in combination with cabergoline, surgery offers a higher disease remission rate than either drug or operation alone.

A scoping review to understand the indications, effectiveness, and limitations of cabergoline in radiological and biochemical remission of prolactinomas

Cabergoline has long been used in the medical management of prolactin-secreting pituitary adenomas. However, there is contradicting and inadequate evidence on the efficacy of cabergoline in achieving radiological and biochemical remission in prolactinoma. This article presents scoping review of evidence in cabergoline achieving radiological and biochemical remission in cases of prolactinoma. We have used a recommended scoping review methodology to map and summarize existing research evidence and identify knowledge gaps. The review process was conducted according to the PRISMA-ScR guidelines (Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews). The selection of studies was based on the criteria defined. Essential information such as reference details, study characteristics, topics of interest, main findings, and the study author's conclusion are presented in text and tables. With the study selection process, eight publications were finally included-one systematic review and meta-analysis, one RCT, and six primary studies. Cabergoline is effective in achieving biochemical and radiological remission in cases of prolactinoma. We identified several knowledge gaps with the scoping review and directions for future studies. Future studies, including randomized studies, will help address challenging questions associated with the management of prolactinoma.

Prolactinomas

Hyperprolactinemia, defined by a level of serum prolactin above the standard upper limit of normal range, is a common finding in clinical practice and prolactinomas are the main pathological cause. Prolactinomas lead to signs and symptoms of hormone oversecretion, such as galactorrhea and hypogonadism, as well as symptoms of mass effect, including visual impairment, headaches and intracranial hypertension. Diagnosis involves prolactin measurement and sellar imaging, but several pitfalls are involved in this evaluation, which may difficult the proper management. Treatment is medical in the majority of cases, consisting of dopamine agonists, which present high response rates, with a very favorable safety profile. Major adverse effects that should be monitored consist of cardiac valvulopathy and impulse control disorders. Other treatment options include surgery and radiotherapy. Temozolomide may be used for aggressive or malignant carcinomas. Finally, pregnancy outcomes are similar to general population even when dopamine agonist treatment is maintained.

Long-term response to cabergoline and multi-modal treatment in men with macroprolactinoma: Does size really matter?

OBJECTIVE

To study the outcome of men with macroprolactinoma following cabergoline treatment based on tumour size.

DESIGN

Retrospective cohort study.

METHODS

The study included 94 men, divided into three groups according to adenoma diameter: 10-19 mm (Group A, n = 36); 20-39 mm (Group B, n = 41); or ≥40 mm (Group C, giant prolactinomas, n = 17). Patients were followed for a mean of 7.5 years with sellar magnetic resonance imaging, visual fields and hormone measurements.

RESULTS

Mean baseline prolactin was 767, 2090 and 24,806 ng/ml in Groups A, B and C, respectively (p < .01). Prolactin suppression below three times the upper limit of normal (ULN) was achieved in 34 (94%; mean weekly cabergoline dose of 1.2 mg), 37 (90%; cabergoline dose, 2.1 mg) and 15 (88%; cabergoline dose, 2.8 mg) men (p = .31) in each group. After excluding patients who underwent surgery and radiotherapy, cabergoline suppressed prolactin below three times ULN in 32/35 (91%), 29/37 (78%) and 11/14 (79%) men in Groups A, B and C, respectively (p = .27). Visual deficits were observed in 5 (14%), 12 (29%) and 10 (59%) patients (p < .01); improvement was achieved in 5/5 (100%), 11/12 (92%) and 10/10 (100%) of men in Groups A, B and C. Low baseline testosterone was measured in 26 (72%), 39 (95%) and 17 (100%) patients in the three groups (p < .01). Following multi-modal treatment, hypogonadism persisted in 3 (8%), 5 (12%) and 2 (12%) men, respectively (p = .85).

CONCLUSION

Macroprolactinomas in men were controlled with cabergoline in 84% of cases, independent of tumour size. Pituitary surgery and adjuvant radiotherapy further improved long-term response to 91%.

Application of Stem Cell Therapy for Infertility

Infertility creates an immense impact on the psychosocial wellbeing of affected couples, leading to poor quality of life. Infertility is now considered to be a global health issue affecting approximately 15% of couples worldwide. It may arise from factors related to the male (30%), including varicocele, undescended testes, testicular cancer, and azoospermia; the female (30%), including premature ovarian failure and uterine disorders; or both partners (30%). With the recent advancement in assisted reproduction technology (ART), many affected couples (80%) could find a solution. However, a substantial number of couples cannot conceive even after ART. Stem cells are now increasingly being investigated as promising alternative therapeutics in translational research of regenerative medicine. Tremendous headway has been made to understand the biology and function of stem cells. Considering the minimum ethical concern and easily available abundant resources, extensive research is being conducted on induced pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSC) for their potential application in reproductive medicine, especially in cases of infertility resulting from azoospermia and premature ovarian insufficiency. However, most of these investigations have been carried out in animal models. Evolutionary divergence observed in pluripotency among animals and humans requires caution when extrapolating the data obtained from murine models to safely apply them to clinical applications in humans. Hence, more clinical trials based on larger populations need to be carried out to investigate the relevance of stem cell therapy, including its safety and efficacy, in translational infertility medicine.

Efficacy and safety in the treatment of hyperprolactinemia: A systematic review and network meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Hyperprolactinemia is a neuroendocrine disease that is responsible for a quarter of cases of secondary amenorrhea, which can lead to infertility in women. Dopaminergic agonists (bromocriptine, cabergoline, quinagolide) can be used in the treatment. However, there is a lack of secondary studies that compare their efficacy and safety, especially through a network meta-analysis. Thus, to contribute to the decision-making, a systematic review and network meta-analyses (NMA) were performed to evaluate the efficacy and safety of dopaminergic agonists in the treatment of hyperprolactinemia.

METHODS

Randomized clinical trials (RCT) were retrieved through PubMed, Web of Science and Scopus databases. The efficacy and safety of the drugs were compared, considering the following outcomes: prolactin (PRL) levels, number of patients with galactorrhoea, menstrual irregularities and adverse drug reactions. NMA was built for each outcome. Results were reported as odds ratios (OR) with 95% credibility intervals. Ranking probabilities were calculated by surface under the cumulative ranking analysis (SUCRA) and Stochastic multicriteria acceptability analysis (SMAA).

RESULTS AND DISCUSSION

Seventeen RCTs were included in the systematic review and fifteen in the meta-analyses. The drugs had similar efficacy, considering the PRL levels. The SUCRA analysis showed that quinagolide (0.075 and 0.05 mg/day) was superior for reducing irregular menstruation, whereas bromocriptine was the best (97%) for galactorrhoea. Cabergoline proved to be the safest drug, except for abdominal pain at a dose of 1 mg/week. The SMAA demonstrated similar results to SUCRA.

WHAT IS NEW AND CONCLUSION

This is the first network meta-analysis that evaluated the efficacy and safety of dopaminergic agonists in the treatment of hyperprolactinemia. The results of this review revealed that these drugs have similar efficacy, but cabergoline has a better safety profile.

Hypeprolactinemia: still an insidious diagnosis

Hyperprolactinemia can have different causes: physiological, pharmacological, and pathological. When investigating the etiology of hyperprolactinemia, clinicians need to be aware of several conditions leading to misdiagnosis. The most popular pitfalls are: acute physical and psychological stress, macroprolactin, hook effect, even though antibodies interferences and biotine use have to be considered. A 52-year-old woman was referred to Endocrinology clinic for oligomenorrhoea and headache. She worked as a butcher. Hormonal evaluation showed very high PRL (305 ng/ml, reference interval: <24 ng/ml) measured with the ECLIA immunoassay analyzer Elecsys 170. The patient's pituitary MRI was normal and macroprolactin was normal. Hormonal workup showed LH: 71.5 mU/ml (2-10.9 mU/ml), FSH: 111.4 mU/ml (3.9-8.8 mU/ml), Estradiol: 110.7 pg/mL (27-122 pg/ml). Since an interference was suspected, the sample was sent to another laboratory using a different assay. After antibody blocking tubes treatment (Heterophilic Blocking Tube, Scantibodies) PRL was 28.8 ng/ml (reference interval < 29.2 ng/ml). Analytical interference should be suspected when assay results are not consistent with the clinical picture. Endogenous antibodies (EA) include heterophile, human anti-animal, autoimmune and other nonspecific antibodies, and rheumatoid factors, that have structural similarities and can cross-react with the antibodies employed by the immunoassay, causing hyperprolactinemia misdiagnosis. The patient's job (butcher), led us to suspect the presence of anti-animal antibodies. Clinicians should also carefully investigate the use of supplements. Biotin can falsely increase hormone concentration in competitive assays. Many clinicians are still not informed about these pitfalls that are not mentioned in some recent reviews on PRL measurement.

Suppression of Breast Cancer by Small Molecules That Block the Prolactin Receptor

Simple Summary

Unabated tumor growth, metastasis, and resistance to hormone therapy and/or to chemotherapy constitute serious impediments for combating breast cancer (BC). With the exception of targeted anti-HER2/neu therapy and combination therapies, there have been no radical changes in the standard of care for BC patients in the past two decades. In addition, there are only limited options for treating BC-derived brain metastases that cause high morbidity and mortality. This report describes the use of high throughput screening (HTS) for identifying novel small molecules that blocked the prolactin receptor (PRLR) and suppressed BC in a laboratory setting. These small molecules have a great potential to become effective therapeutics in patients with BC.

Abstract

Prolactin (PRL) is a protein hormone which in humans is secreted by pituitary lactotrophs as well as by many normal and malignant non-pituitary sites. Many lines of evidence demonstrate that both circulating and locally produced PRL increase breast cancer (BC) growth and metastases and confer chemoresistance. Our objective was to identify and then characterize small molecules that block the tumorigenic actions of PRL in BC. We employed three cell-based assays in high throughput screening (HTS) of 51,000 small molecules and identified two small molecule inhibitors (SMIs), named SMI-1 and SMI-6. Both compounds bound to the extracellular domain (ECD) of the PRL receptor (PRLR) at 1–3 micromolar affinity and abrogated PRL-induced breast cancer cell (BCC) invasion and malignant lymphocyte proliferation. SMI-6 effectively reduced the viability of multiple BCC types, had much lower activity against various non-malignant cells, displayed high selectivity, and showed no apparent in vitro or in vivo toxicity. In athymic nude mice, SMI-6 rapidly and dramatically suppressed the growth of PRL-expressing BC xenografts. This report represents a pre-clinical phase of developing novel anti-cancer agents with the potential to become effective therapeutics in breast cancer patients.

Pituitary Adenomas: From Diagnosis to Therapeutics

Pituitary adenomas are tumors that arise in the anterior pituitary gland. They are the third most common cause of central nervous system (CNS) tumors among adults. Most adenomas are benign and exert their effect via excess hormone secretion or mass effect. Clinical presentation of pituitary adenoma varies based on their size and hormone secreted. Here, we review some of the most common types of pituitary adenomas, their clinical presentation, and current diagnostic and therapeutic strategies.

Gamma knife radiosurgery for high-risk lactotroph adenomas: Long-term results

Gamma Knife radiosurgery (GKRS) for lactotroph adenomas (LAs) or prolactinomas is limited due to the effectiveness of medical treatments and surgery. Cases who are refractory to medical treatment and/or surgery may be managed with GKRS. We aimed to describe the effectiveness of GKRS for high-risk lactotroph adenomas (HRLAs) and LAs that were medically and surgically refractory. We analyzed our series of patients with HRLAs and LAs who were managed with GKRS following failed medical treatment and surgery and who had at least three years of follow-up. A total of 52 patients (22 HRLAs and 30 LAs) were included in the analysis of radiological, endocrine, and clinical outcomes. Radiological control was achieved in 68.2% of subjects in the HRLA group and 96.7% of subjects in the LA group. Hormonal control was achieved in 68.2% of patients in the HRLA group and 80% of patients in the LA group. On univariate analysis, hormonal control was significantly associated with pre-treatment volume (p = 0.007), higher margin dose (p = 0.002) and Ki-67 proliferative index (p = 0.007). Complications involved new pituitary hormone deficiencies in 19.2% of patients and asymptomatic peripheral visual field defect in 1.9% of patients. To the best of our knowledge, this is the first study to examine the effectiveness of GKRS in LAs and HRLAs, with the highest median follow-up in the literature. High hormonal control rate, even in HRLAs, and lower complication rates suggest that GKRS should be part of the techniques for managing treatment refractory LAs.

Surgery and Medical Treatment in Microprolactinoma: A Systematic Review and Meta-Analysis

OBJECTIVE

Dopamine agonists (DAs) are recommended as the first-line treatment for prolactinomas; however, tumour recurrence after drug withdrawal remains a clinical problem. Recent studies have reported high remission rates via surgery in microprolactinomas. The aim of this systematic review and meta-analysis was to compare the clinical result of DA treatment with surgery as initial therapy in patients with treatment-naive microprolactinoma.

METHODS

A comprehensive literature search for studies and reports regarding microprolactinoma patients treated with DAs and/or surgery published between January 1970 and November 2020 was conducted using four electronic databases (PubMed, Embase, Google Scholar, and the Cochrane Library). Clinical treatment outcome was evaluated by the biochemical remission of serum prolactin level to normal after treatment. The I ² statistic was used to quantify heterogeneity. Pooled data were analysed according to a random effect model.

RESULTS

Eighteen studies with 661 patients were included for analysis. The DA treatment group achieved a higher remission rate at ≥12 months follow-up (96% vs. 86%; P=0.019). Surgery showed a higher remission rate than the DA treatment group after the treatment withdrawal (78% vs. 44%; P=0.003). Patients with preoperative prolactin level of ≤200 ng/mL had a higher remission rate than patients with preoperative prolactin level of >200 ng/mL (92% vs. 40%; P=0.029).

CONCLUSION

Surgery showed a high remission rate in treatment-naive microprolactinoma patients after treatment withdrawal and may be an alternative first-line treatment strategy in addition to DAs, particularly in patients with a preoperative prolactin level of ≤200 ng/mL.

Cabergoline as an adjuvant to standard heart failure treatment in peripartum cardiomyopathy: A case report and review of the literature

Introduction

Peripartum cardiomyopathy (PPCM) is a rare and idiopathic form of dilated cardiomyopathy presenting late in pregnancy or early postpartum. Since the 16-kDa fragment of prolactin has been identified as a key factor in the pathophysiology of PPCM, prolactin inhibitors have been used as an adjuvant to standard heart failure treatment. Although bromocriptine is the current first choice, promising results have been reported with cabergoline, albeit scant.

Case Presentation

We presented the case of a 41-year-old woman who received a diagnosis of PPCM one week after delivery and was successfully treated with cabergoline, finally experiencing a complete recovery.

Conclusion

The case adds to the scant evidence supporting the use of cabergoline in PPCM patients. We argue that the favorable pharmacokinetic and metabolic profiles of this drug should prompt its consideration as a valid alternative prolactin inhibitor in these critical patients.

•

Peripartum cardiomyopathy is a rare and life-threatening form of dilated cardiomyopathy.

•

The management relies on the standard recommendations for heart failure with systolic dysfunction.

•

The use of prolactin inhibitors represents the only specific and evidence-based treatment available.

•

Given the favorable pharmacokinetics, cabergoline should be considered as the first-line prolactin inhibitor.

Predictors of the Response to Dopaminergic Therapy in Patients With Prolactinoma

PURPOSE

Withdrawal of dopamine agonist (DA) therapy in patients with prolactinoma who are controlled by a small dose of medication is recommended by several guidelines. So far, the likelihood of reaching withdrawal conditions based on baseline characteristics remains uncertain.

METHODS

We retrospectively examined early clinical, radiological, or biochemical features that may predict the likelihood of reaching withdrawal conditions in prolactinoma patients. Data were obtained in a single academic medical center in the United States from patients seen between 2000 and 2018. Using multiple logistic regression, we compared patients who reached withdrawal conditions with those who did not.

RESULTS

Of 213 patients, 78 (36.6%) reached withdrawal conditions after at least 2 years of DA treatment. Initial maximal tumor diameter was significantly smaller in those who reached withdrawal conditions than in those who did not. Percent prolactin change at the first check from initiation of DA therapy and parasellar invasiveness were predictors of reaching withdrawal conditions. With constant independent variables, there was a 7% increase in odds for reaching withdrawal conditions for every 1% decrease in percent prolactin change at first check after DA therapy start (P = 0.0000). Parasellar invasion decreased the odds of reaching withdrawal conditions by 84% (P = 0.0000).

CONCLUSIONS

DA remains a potential life-long treatment modality for most prolactinoma patients. Patients with parasellar invasiveness and low prolactin percent change from baseline to first prolactin check are more likely to require long-term treatment.

The Menstrual Disturbances in Endocrine Disorders: A Narrative Review

CONTEXT

Menstrual cycle is considered the fifth vital sign among women. This study aimed to summarize the menstrual disturbances in different endocrine disorders.

EVIDENCE ACQUISITION

In this narrative review, relevant studies (up to December 2019) were searched based on the MeSH keywords diabetes, polycystic ovary syndrome, Cushing's syndrome, thyroid dysfunction, hyperprolactinemia, menstrual cycle, uterine bleeding, and menstruation. Databases used for searching articles included Google Scholar, Scopus, PubMed, and Web of science for observational, experimental, and review studies.

RESULTS

Endocrine disorders trigger the onset of menstrual disturbance across the reproductive lifespan of women. Endocrine glands (pituitary, thyroid, pancreas, adrenal, and ovaries) have a functional role in endocrine regulation of the menstrual cycle. According to available evidence, oligomenorrhea (cycles longer than 35 days) is the most common menstrual disturbance among endocrine disorders (thyrotoxicosis, hypothyroidism, polycystic ovary syndrome, Cushing's syndrome, and diabetes). Complex endocrine pathways play an essential role in a women's menstrual calendar.

CONCLUSIONS

The menstrual cycle length and amount of bleeding can be indicative of endocrine disorders. Further studies are needed to identify the unknowns about the association between endocrine disorders and the menstrual cycle.

Autophagy and Pituitary Adenoma

Pituitary adenomas (PAs) are common, benign intracranial tumors that are usually effectively controlled with surgery, pharmacotherapy or radiotherapy. Some PAs against which conventional treatment is ineffective are great clinical challenges at present. Autophagy is a widespread physiological process in cells. Through autophagy, cells can degrade damaged or redundant proteins and organelles and achieve the recycling of intracellular substances to maintain the homeostasis of the intracellular environment. An increasing number of studies have demonstrated the importance of autophagy in tumor therapy. Both radiotherapy and chemotherapy can induce autophagy, which plays different roles in the course of therapy. In recent years, there has been growing interest in the role of autophagy during the treatment of PAs. This chapter reviews the recent progress of research on autophagy in PA and the autophagic mechanisms in the treatment of PA.

The benefit and risk of stereotactic radiosurgery for prolactinomas: an international multicenter cohort study

OBJECTIVE

The most common functioning pituitary adenoma is prolactinoma. Patients with medically refractory or residual/recurrent tumors that are not amenable to resection can be treated with stereotactic radiosurgery (SRS). The aim of this multicenter study was to evaluate the role of SRS for treating prolactinomas.

METHODS

This retrospective study included prolactinomas treated with SRS between 1997 and 2016 at ten institutions. Patients' clinical and treatment parameters were investigated. Patients were considered to be in endocrine remission when they had a normal level of prolactin (PRL) without requiring dopamine agonist medications. Endocrine control was defined as endocrine remission or a controlled PRL level ≤ 30 ng/ml with dopamine agonist therapy. Other outcomes were evaluated including new-onset hormone deficiency, tumor recurrence, and new neurological complications.

RESULTS

The study cohort comprised 289 patients. The endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years after SRS, respectively. Following SRS, 25% of patients (72/289) had new hormone deficiency. Sixty-three percent of the patients (127/201) with available data attained endocrine control. Three percent of patients (9/269) had a new visual complication after SRS. Five percent of the patients (13/285) were recorded as having tumor progression. A pretreatment PRL level ≤ 270 ng/ml was a predictor of endocrine remission (p = 0.005, adjusted HR 0.487). An increasing margin dose resulted in better endocrine control after SRS (p = 0.033, adjusted OR 1.087).

CONCLUSIONS

In patients with medically refractory prolactinomas or a residual/recurrent prolactinoma, SRS affords remarkable therapeutic effects in endocrine remission, endocrine control, and tumor control. New-onset hypopituitarism is the most common adverse event.

The Role of Dopamine Agonists in Pituitary Adenomas

Dopamine agonist therapy is the primary therapy for prolactin-secreting adenomas and usually results in normoprolactinemia, eugonadism, and tumor reduction. Cabergoline is superior to bromocriptine with regard to efficacy and tolerance. Withdrawal of cabergoline can be attempted in patients with normal prolactin levels on low doses of medication and evidence of radiographic tumor involution. Dopamine agonists have been used off label in patients with acromegaly, Cushing disease, and nonfunctioning adenomas. A trial of cabergoline monotherapy can be effective in patients with biochemically mild acromegaly. Cabergoline combination with somatostatin receptor ligands or pegvisomant improves insulin-like growth factor level 1 in majority of patients.

Hyperprolactinaemia in the context of psychiatry

Advocating for good physical healthcare for their patients is of the utmost importance to psychiatrists. This narrative review focuses on one part of this large goal, the topic of hyperprolactinaemia from the perspective of mental healthcare. For psychiatrists this often includes managing raised prolactin levels in the context of medication. However, they must consider the wider differentials of a raised prolactin level and the possible impact of treatments. For that reason, in this review we start with an overview of prolactin physiology before considering hyperprolactinaemia both in the context of antipsychotic therapy and its wider differentials, including prolactinoma. Investigation and management are considered and key practice points developed.

Expression patterns of ERα66 and its novel variant isoform ERα36 in lactotroph pituitary adenomas and associations with clinicopathological characteristics

PURPOSE

The regulatory effects of estradiol on pituitary homeostasis have been well documented. However, the expression patterns of ERα66 and ERα36 and their correlations with the clinical course of postoperative prolactinoma tumors remain unclear.

METHODS

The expression of ERα36, ERα66, Ki67, p53, and CD31 were determined by immunohistochemistry in 62 prolactinoma patients. Snap-frozen tumors and normal pituitaries were also examined by western blotting for estrogen receptor detection.

RESULTS

A broad expression of ERα36 was identified in normal pituitaries. The median scores of ERα36 and ERα66 expression were 8 and 6 in normal pituitaries and 4 and 0 in tumors, respectively. Four phenotypes of ERα36 and ERα66 expression were explored in tumors with regard to sex, invasiveness, dopamine resistance, and recurrence. Low ERα36 expression was associated with tumor invasion and increased Ki67. Low ERα66 expression was associated with tumor invasion, dopamine-agonist resistance, and enhanced tumor size. Multivariable logistic regression analysis showed that low ERα36 expression is an independent risk factor for invasiveness. The significant inverse association of ERα66 with invasiveness, dopamine resistance, and tumor size remained significant after adjustment for sex as a potential confounder. After controlling for sex, the low ERα66/low ERα36 phenotype was 6.24 times more prevalent in invasive tumors than in noninvasive tumors. Although the decreasing trend of CD31 expression from surrounding nontumoral lactotroph adenomas to tumors was similar to that of the estrogen receptors, a significant correlation was not observed here.

CONCLUSION

The decreasing trends of ERα36 and ERα66 expression from normal pituitaries to tumors are associated with aggressive clinical behavior.

Dopamine agonist resistant prolactinomas: any alternative medical treatment?

Consensus guidelines recommend dopamine agonists (DAs) as the mainstay treatment for prolactinomas. In most patients, DAs achieve tumor shrinkage and normoprolactinemia at well tolerated doses. However, primary or, less often, secondary resistance to DAs may be also encountered representing challenging clinical scenarios. This is particularly true for aggressive prolactinomas in which surgery and radiotherapy may not achieve tumor control. In these cases, alternative medical treatments have been considered but data on their efficacy should be interpreted within the constraints of publication bias and of lack of relevant clinical trials. The limited reports on somatostatin analogues have shown conflicting results, but cases with optimal outcomes have been documented. Data on estrogen modulators and metformin are scarce and their usefulness remains to be evaluated. In many aggressive lactotroph tumors, temozolomide has demonstrated optimal outcomes, whereas for other cytotoxic agents, tyrosine kinase inhibitors and for inhibitors of mammalian target of rapamycin (mTOR), higher quality evidence is needed. Finally, promising preliminary results from in vitro and animal reports need to be further assessed and, if appropriate, translated in human studies.

[The effect of the dopamine D2 receptor agonist cabergoline on the content of catecholamines and expression of BDNF mRNA in the rat midbrain and hypothalamus]

AIM

To study an effect of cabergoline on dopamine and noradrenaline concentration and BDNF mRNA level in the rat midbrain and hypothalamus.

MATERIAL AND METHODS

Twenty adult male Wistar rats were used in a single treatment paradigm: animals of the treatment group (n=10) received cabergoline (i.p., 0.5 mg/kg) and the control group (n=10) received an equivalent volume of the solvent. Quantitative analysis for the dopamine (DA) and noradrenaline (NA) was carried out using high-performance liquid chromatography (HPLC) coupled with electrochemical detection. BDNF mRNA levels were studied using quantitative RT-PCR.

RESULTS AND CONCLUSION

Cabergoline significantly increases NA concentration in the midbrain 24 hours after injection: 639.2±64.5 ng/g in the treatment group versus 398.0±66.0 ng/g in the control group (p<0.05), while mean content of DA is not significantly changed (211.4±16.3 ng/g vs 169.7±54.6 ng/g, respectively). Cabergoline does not affect hypothalamic DA and NA levels. The drug increases BDNF mRNA levels by 2-times in the midbrain, but not in the hypothalamus, 24 hours after injection.

Update on Comparative Biology of Elephants: Factors Affecting Reproduction, Health and Welfare

Asian (Elephas maximus) and African (Loxodonta africana) elephants serve as important keystone, umbrella and flagship species. Despite that, population numbers are declining, due mainly to poaching and habitat destruction. Understanding reproductive mechanisms is vital to effective management, particularly insurance populations in captivity, and to that end, long-term biological databases are key to understanding how intrinsic and extrinsic factors affect reproductive function at individual and population levels. Through decades of hormonal and ultrasonographic monitoring, many unique aspects of zoo elephant reproduction have been identified, including differences in luteal steroidogenic activity, follicular maturation, pituitary gonadotropin secretion, fetal development and reproductive tract anatomy. Reproductive problems also hamper captive propagation efforts, particularly those related to abnormal or lack of ovarian cyclicity. Recent large-scale, multi-institutional studies and use of epidemiological approaches have identified factors important for good welfare and reproduction, which include enrichment, feeding diversity, good elephant-keeper relations, social compatibility, exercise, and not being obese. There are notable differences in reproductive mechanisms between Asian and African elephants, as well as the factors that influence reproduction and welfare, suggesting species-targeted management approaches are needed to maximize fitness. In the first edition, we discussed reproductive function in male and female elephants. Since then, a number of significant advances have been made primarily in female elephants, which will be the focus of this updated review.

Functioning Pituitary Adenomas - Current Treatment Options and Emerging Medical Therapies

Pituitary adenomas are benign tumours comprising approximately 16% of all primary cranial neoplasms. Functioning pituitary adenomas (prolactinomas, somatotroph, corticotroph, thyrotroph and rarely gonadotroph adenomas) cause complex clinical syndromes and require prompt treatment to reduce associated morbidity and mortality. Treatment approaches include transsphenoidal surgery, medical therapy and radiation. Medical therapy is the primary therapy for prolactinomas, and surgery by a skilled neurosurgeon is the first-line approach for other functioning pituitary adenomas. A multimodal treatment is frequently necessary to achieve biochemical and clinical control, especially, when surgery is not curative or when medical therapy fails. Several emerging, novel, medical treatments for acromegaly, Cushing's disease and prolactinomas are in phase II and III clinical trials and may become effective additions to the current drug armamentarium. The availability of various management options will allow an individualised treatment approach based on the unique tumour type, clinical situation and patient preference.

No impact of treated hyperprolactinemia on cumulative live birth rate and perinatal outcomes in in vitro fertilization-embryo transfer

AIM

To investigate whether treated hyperprolactinemia has an impact on pregnancy outcomes in in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET).

METHODS

A retrospective cohort study was conducted on 535 women who underwent IVF/ICSI-ET between January 2012 and December 2016, of which 123 had treated hyperprolactinemia (case group), 369 were matched controls. Besides, 43 remained hyperprolactinemic after treatment consisted of abnormal group. Cumulative live birth rate (CLBR) after one oocyte retrieval cycle was taken as the primary outcome. A time-to-event analysis using Fine and Gray's test was used to compare CLBR between case and control groups.

RESULTS

The median prolactin level was 80.00 ng/mL before dopamine agonist treatment in case group, and it reduced to 14.80 ng/mL after the treatment, similar to the level of control group (15.17 ng/mL, P = 0.316). No significant differences in baseline characteristics were found between case and control groups. The CLBR after one oocyte retrieval cycle were 69.1% (85/123) and 66.4% (245/369) in the case group and control group, respectively (P = 0.580). No significant differences were found between case and control groups in perinatal outcomes. Pregnancy and perinatal outcomes of abnormal group were similar to those of case and control groups.

CONCLUSION

Impact of treated hyperprolactinemia on CLBR and perinatal outcomes in IVF-ET was not evident.

Pharmacology of medications used for ovarian stimulation

Medications to stimulate the ovaries may be used to induce ovulation in patients with anovulatory infertility or to hyperstimulate the ovaries in a controlled fashion in ovulatory patients as part of assisted reproductive treatments (ART). The pharmacology of all current major medications used to stimulate ovarian function is reviewed in this article, including letrozole, clomiphene citrate, gonadotropins, and pulsatile gonadotropin releasing hormone (GnRH). Novel potential compounds and adjuvant treatment approaches are also discussed, such as kisspeptin agonists and androgens.

Management of Dopamine Agonist-Resistant Prolactinoma

Dopamine agonists are usually very effective in the treatment of prolactinomas. Nonetheless, a subset of individuals does not respond satisfactorily to these agents, and this resistance is characterized by failure to achieve normoprolactinemia and a 30% or more reduction in maximal tumor diameter (in the case of macroprolactinoma) under maximally tolerated doses. The overall prevalence of dopamine agonist resistance is 20-30% for bromocriptine (BRC) and around 10% for cabergoline (CAB). The 2 main predictive factors are male gender and tumor invasiveness. The management of drug-resistant prolactinomas includes several options. Any BRC-resistant patient should be switched to CAB which will normalize prolactin in 80% of patients. As long as adverse effects do not develop, dose escalation of CAB is reasonable, with the expectation that subsequent dose reduction will be possible. Echocardiographic monitoring is advised in such patients because of the potential association with cardiac valvular fibrosis. Also, maintaining maximal CAB doses at 3.5 mg/week may lead to progressive hormonal control in a significant proportion of patients. Complete resistance to CAB is infrequent. In a study of 122 patients with a macroprolactinoma, only 7 (6%) could not achieve control despite maximal CAB doses for > 12 months. A large resistant prolactinoma is also an indication for transsphenoidal neurosurgery, aiming at a debulking which may improve postoperative medical control. For patients who harbor aggressive prolactinomas, radiotherapy may be considered. However, normal prolactinemia will eventually occur in only one-third of patients after many years. Finally, temozolomide may be a therapeutic option in malignant/aggressive prolactinomas.

Management of antipsychotic-induced hyperprolactinaemia

Hyperprolactinaemia is a common endocrine disorder that can be associated with significant morbidity. Antipsychotic medications are frequently linked to hyperprolactinaemia. This disorder usually presents as menstrual problems in women and sexual problems in men, which affect the patients' quality of life and adherence to antipsychotic treatment. In the past, treatment for hyperprolactinaemia was recommended only for symptomatic patients. However, it has become clear that persistent asymptomatic hyperprolactinaemia can be associated with long-term physical morbidities such as osteoporosis and possibly breast cancer. Hence, it is imperative that hyperprolactinaemia is managed even if asymptomatic when initially detected. This article discusses the various management options, such as reducing the dose of antipsychotic medication, switching to a prolactin-sparing antipsychotic and adding aripiprazole to the treatment regimen.

Learning Objectives

• Understand the physiology of the prolactin hormone

• Be able to judge when to intervene if a patient on an antipsychotic medication presents with hyperprolactinaemia

• Learn about the different treatment options

Pediatric prolactinoma: initial presentation, treatment, and long-term prognosis

Prolactinoma is a rare pituitary adenoma secreting prolactin. Studies on diagnostics, treatment, and prognosis in pediatric prolactinoma patients are rare. We analyzed clinical presentation, response to treatment, and prognosis of 27 pediatric prolactinoma patients (10 m/17 f. based on patients' records. Tumors included 6 microadenomas (tumor volume: median 0.2 cm³, range 0.01-0.4 cm³; serum prolactin at diagnosis: median 101 ng/ml, range 33-177 ng/ml), 15 macroadenomas (volume: median 3.3 cm³, range 0.4-25.8 cm³; prolactin: median 890 ng/ml, range 87-8624), and 3 giant adenomas (volume: median 44.5 cm³, range 38.6-93.5 cm³; prolactin: median 4720 ng/ml, range 317-10,400); data for 3 patients were not available. Dopamine agonist treatment (n = 22) was safe and effective, leading to reductions in tumor size (p < 0.01) and prolactin levels (p < 0.01). Threat to vision was the indication for decompressing surgery in three of seven operated patients. No patient was irradiated. Long-term functional capacity was not impaired when compared with other sellar masses (n = 235).

CONCLUSION

In pediatric prolactinoma, diagnosis is based on hyperprolactinemia and imaging. Dopamine agonist treatment is effective and safe. Overall survival and functional capacity as a measure of quality of survival were not impaired, indicating an optimistic prognosis. Surgery should be considered only in emergency situations of threatened visual function, not presenting a fast response to dopamine agonist treatment. Severe side effects of medication and lack of efficacy should be considered as contraindications. What is Known: • In pediatric prolactinoma-a very rare pediatric neuroendocrinological disease-gender-related differences in terms of clinical presentation at initial diagnosis are known. • Due to the rareness of the disease, reports on long-term outcome and prognosis after childhood-onset prolactinoma based on prospective follow-up are not published. What is New: • Dopamine agonist treatment is efficient and safe for tumor volume reduction in pediatric prolactinoma and surgical interventions are recommended only for decompression of the optic chiasm in case of threat to vision. In case of inefficient response to medication, side effects or parental refuse, alternative therapeutic options should be considered. • Quality of life in terms of survival and functional capacity was not impaired in pediatric prolactinoma patients when compared with 235 long-term survivors of different sellar masses.

The Chance of Permanent Cure for Micro- and Macroprolactinomas, Medication or Surgery? A Systematic Review and Meta-Analysis

Background: This meta-analysis aims to evaluate the long-term efficacy of medication treatment vs. surgery treatment in patients with prolactinomas. Methods: An electronic literature search was performed using MEDLINE, EMBASE and Web of Science databases for studies dated before July in 2018. Patients with prolactinomas received primary dopamine agonists (DAs) treatment or primary surgical interventions were included in this study. A systematic review and meta-analysis were performed in pertinent studies meeting eligible criteria. The clinical outcome was measured by the long-term remission rate of prolactin (PRL) in each cohort. The pooled data was analyzed according to a random effect model. Results: Thirteen publications with total 809 patients were included in the final meta-analysis. In the overall patients with prolactinomas, long-term remission rate was achieved in 88% patients treated with surgeries and in 52% patients treated with DAs (P = 0.001). The long-term remission rates in surgery cohort were also significantly higher than medication cohort in both microprolactinomas and macroprolactinomas (91 vs. 60%, P = 0.002; 77 vs. 43%, P = 0.003). Conclusions: Patients with prolactinomas, especially microprolactinomas, can consider transsphenoidal surgery as an alternative first-line treatment strategy. After receiving primary surgical intervention, administration of DAs should be considered based on the postoperative PRL level to achieve the best long-term remission rate.

Hyperprolactinaemia in male infertility: Clinical case scenarios

Objective

To explore the evaluation, treatment and impact of hyperprolactinaemia on male infertility and testicular function, as hyperprolactinaemia is commonly detected during the evaluation of infertile men.

Methods

A literature search was performed using MEDLINE/PubMed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all studies exploring hyperprolactinaemia in male infertility.

Results

Elevated levels of serum prolactin have a detrimental effect on male reproduction through inhibition of the pulsatile release of gonadotrophins from the anterior pituitary gland, and a direct effect on spermatogenesis. Treatment of confirmed hyperprolactinaemia with dopamine agonists leads to significant improvements in both semen parameters and hormone levels.

Conclusion

Hyperprolactinaemia, both directly and indirectly, has a negative effect on sperm production, and its detection and management in men seeking fertility is mandatory.