Does hypopituitarism recover when macroprolactinomas are treated with cabergoline?

Metabolic and inflammatory parameters in relation to baseline characterization and treatment outcome in patients with prolactinoma: insights from a retrospective cohort study at a single tertiary center

Background

Prolactinomas (PRLs) are prevalent pituitary adenomas associated with metabolic changes and increased cardiovascular morbidity. This study examined clinical, endocrine, metabolic, and inflammatory profiles in PRL patients, aiming to identify potential prognostic markers.

Methods

The study comprised data from 59 PRL patients gathered in a registry at the University Hospital of Zurich. Diagnostic criteria included MRI findings and elevated serum prolactin levels. We assessed baseline and follow-up clinical demographics, metabolic markers, serum inflammation-based scores, and endocrine parameters. Treatment outcomes were evaluated based on prolactin normalization, tumor shrinkage, and cabergoline dosage.

Results

The PRL cohort exhibited a higher prevalence of overweight/obesity, prediabetes/diabetes mellitus, and dyslipidemia compared to the general population. Significant correlations were found between PRL characteristics and BMI, HbA1c, and fT4 levels. Follow-up data indicated decreases in tumor size, tumor volume, prolactin levels, and LDL-cholesterol, alongside increases in fT4 and sex hormones levels. No significant associations were observed between baseline parameters and tumor shrinkage at follow-up. A positive association was noted between PRL size/volume and the time to achieve prolactin normalization, and a negative association with baseline fT4 levels.

Conclusion

This study underscores the metabolic significance of PRL, with notable correlations between PRL parameters and metabolic indices. However, inflammatory markers were not significantly correlated with patient stratification or outcome prediction. These findings highlight the necessity for standardized follow-up protocols and further research into the metabolic pathogenesis in PRL patients.

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.

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.

Are dopamine agonists still the first-choice treatment for prolactinoma in the era of endoscopy? A systematic review and meta-analysis

Background

For prolactinoma patients, dopamine agonists (DAs) are indicated as the first-line treatment and surgery is an adjunctive choice. However, with the development of surgical technique and equipment, the effect of surgery has improved. The aim of this study was to assess the efficacy and safety of surgery versus DAs in patients with different types of prolactinomas.

Methods

A systematic search of literature using Web of Science, PubMed, Cochrane Library, and Clinical Trial databases was conducted until July 12, 2019. Prolactinoma patients treated with DAs (bromocriptine or cabergoline) or surgery (microscopic or endoscopic surgery) were included. Outcomes included the biochemical cure rate, recurrence rate, prolactin level, improvement rates of symptoms, and incidence rates of complications. A random-effects model was used to pool the extracted data. Qualitative comparisons were conducted instead of quantitative comparison.

Results

DAs were better than surgery in terms of the biochemical cure rate (0.78 versus 0.66), but surgery had a much lower recurrence rate (0.19 versus 0.57). Full advantages were not demonstrated in improvement rates of symptoms and incidence rates of complications with both treatment options. In microprolactinoma patients, the biochemical cure rate of endoscopic surgery was equal to the average cure rate of DAs (0.86 versus 0.86) and it surpassed the biochemical cure rate of bromocriptine (0.86 versus 0.76). In macroprolactinoma patients, endoscopic surgery was slightly higher than bromocriptine (0.66 versus 0.64) in terms of the biochemical cure rate.

Conclusion

For patients with clear indications or contraindications for surgery, choosing surgery or DAs accordingly is unequivocal. However, for patients with clinical equipoise, such as surgery, especially endoscopic surgery, in microprolactinoma and macroprolactinoma patients, we suggest that neurosurgeons and endocrinologists conduct high-quality clinical trials to address the clinical equipoise quantitatively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41016-022-00277-1.

Epidemiology of Male Hypogonadism

The epidemiology of male hypogonadism has been understudied. Of the known causes of endogenous androgen deficiency, only Klinefelter syndrome is common with a likely population prevalence of greater than 5:10,000 men (possibly as high as 10-25:10,000). Mild traumatic injury might also be a common cause of androgen deficiency (prevalence 5-10:10,000 men), but large, long-term studies must be completed to confirm this prevalence estimation that might be too high. The classic causes of male androgen deficiency-hyperprolactinemia, pituitary macroadenoma, endogenous Cushing syndrome, and iron overload syndrome-are rare (prevalence < 10,000 men).

Efficacy and Cerebrospinal Fluid Rhinorrhea after Cabergoline Treatment in Patients with Bioactive Macroprolactinoma

Predicting dopamine agonist resistance in patients with macroprolactinoma is essential for clinicians to prevent treatment failure and subsequent complications such as medication-induced cerebrospinal fluid (CSF) rhinorrhea. We evaluated the features of patients with cabergoline resistance and CSF rhinorrhea in patients with prolactinomas with prolactin levels ≥1000 ng/mL. A total of 140 patients who were newly diagnosed with prolactinoma secreting only prolactin ≥1000 ng/mL and treated with cabergoline for the first time were included in this study. Based on the hormonal and radiologic response of the prolactinoma, the patients were divided into responders and non-responders. Non-responders (36/140, 25.8%) included a higher number of patients receiving hormone replacement than responders (responders, n (%) = 12(11.5) vs. non-responders = 13(36.1), p = 0.001). In propensity score matching analysis, patients who developed CSF rhinorrhea presented more frequent hormone deficiency than responders regardless of initial cabergoline dose. Hormone deficiency was associated with a greater odds ratio for the risk of non-responders (adjusted odds ratio = 5.13, 95% CI 1.96-13.46, p = 0.001). Cabergoline was effective in bioactive macroprolactinoma. Furthermore, initial cabergoline dose was not significantly associated with long-term responsiveness and development of CSF rhinorrhea but the hypopituitarism was independently associated with an increased risk of cabergoline resistance and CSF rhinorrhea.

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

CONTEXT

Data are limited regarding prevalence, predictors, and mechanisms of persistent hypogonadotropic hypogonadism (HH) in males with a macroprolactinoma who achieve normoprolactinemia on dopamine-agonist therapy. None of the previous studies provide cutoffs to predict the achievement of eugonadism.

OBJECTIVE

The objective of this work is to evaluate the prevalence of persistent HH and its determinants in men with a macroprolactinoma who achieve normoprolactinemia on cabergoline monotherapy.

DESIGN AND SETTING

This retrospective study with prospective cross-sectional evaluation took place at a tertiary health care center.

PATIENTS

Study participants included men with a macroprolactinoma and baseline HH who achieved normoprolactinemia on cabergoline monotherapy.

MAIN OUTCOME MEASURES

Outcome measures of this study included the prevalence of persistent HH and its predictors.

RESULTS

Thirty participants (age, 38.3 ± 10.1 years) with baseline tumor size of 4.08 ± 1.48 cm and median (interquartile range) prolactin of 2871 ng/mL (range, 1665-8425 ng/mL) were included. Eight of 30 participants achieved eugonadism after a median follow-up of 3 years. Patients with persistent HH had suppression of the luteinizing hormone (LH)-testosterone axis with sparing of other anterior pituitary hormonal axes, including follicle-stimulating hormone-inhibin B. Baseline prolactin (1674 vs 4120 ng/mL; P = .008) and maximal tumor diameter (2.55 ± 0.36 vs 4.64 ± 1.32 cm; P = .003) were lower in patients who achieved eugonadism. Baseline maximal tumor diameter less than or equal to 3.2 cm (sensitivity: 75%, specificity: 63.6%) and serum prolactin less than or equal to 2098 ng/mL (sensitivity: 87.5%, specificity: 77.3%) best predicted reversal of HH.

CONCLUSION

Recovery of the LH-testosterone axis occurred in 26.7% of men with a macroprolactinoma who achieved normoprolactinemia on cabergoline monotherapy. Higher baseline tumor size and serum prolactin predict persistent HH. Our data favor chronic functional modification of the hypothalamic-pituitary-gonadal axis over gonadotroph damage as the cause of persistent HH.

Adrenal insufficiency: Physiology, clinical presentation and diagnostic challenges

Adrenal insufficiency (AI) is a serious condition, which can arise from pathology affecting the adrenal gland itself (primary adrenal insufficiency, PAI), hypothalamic or pituitary pathology (secondary adrenal insufficiency, SAI), or as a result of suppression of the hypothalamic-pituitaryadrenal (HPA) axis by exogenous glucocorticoid therapy (tertiary adrenal insufficiency, TAI). AI is associated with an increase in morbidity and mortality and a reduction in quality of life. In addition, the most common cause of PAI, autoimmune adrenalitis, may be associated with a variety of other autoimmune disorders. Untreated AI can present with chronic fatigue, weight loss and vulnerability to infection. The inability to cope with acute illness or infection can precipitate life-threatening adrenal crisis. It is therefore a critical diagnosis to make in a timely fashion, in order to institute appropriate management, aimed at reversing chronic ill health, preventing acute crises, and restoring quality of life. In this review, we will describe the normal physiology of the HPA axis and explain how knowledge of the physiology of this axis helps us understand the clinical presentation of AI, and forms the basis for the biochemical investigations which lead to the diagnosis of AI.

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.

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

Dopamine agonist therapy induces significant recovery of HPA axis function in prolactinomas independent of tumor size: a large single center experience

Our objective was to compare prevalence and rates of recovery of hypothalamic-pituitary-adrenal axis dysfunction in prolactinoma patients before and after dopamine agonist therapy with nonfunctioning pituitary adenoma patients pre-transsphenoidal and post-transsphenoidal surgery. We retrospectively compared hypothalamic-pituitary-adrenal axis function in patients with prolactinomas naïve to dopamine agonist therapy with a cohort of nonfunctioning pituitary adenoma patients matched for gender and tumor size by classification (n = 57; 30 male/27 female; 27 microadenoma/30 macroadenoma). Patients with <52 weeks follow up, previous medical therapy, surgery, or radiation therapy were excluded. At baseline, there was no difference between groups for age, mean tumor size, or prevalence of adrenal insufficiency. Recovery from baseline adrenal insufficiency was demonstrated in patients with microprolactinomas and macroprolactinomas at a 52 week follow up (p  = 0.003 and p  = 0.004). These rates were similar to nonfunctioning pituitary adenoma patients after surgery. We show, in a large uniform study, that adrenal insufficiency significantly recovered after dopamine agonist treatment, independent of tumor size and gender in patients with prolactinomas naïve to therapy.

Long-term outcome of macroprolactinomas

OBJECTIVE

Management of macroprolactinomas has dramatically changed in recent decades, from surgical to medical treatment as first-line therapy, with the development of dopamine agonists (DA). But few data exist on the long-term outcome of these patients.

PATIENTS AND METHODS

Retrospective descriptive multicenter study of patients with macroprolactinoma followed for at least 5 years between 1973 and 2008 at the University Hospitals of Strasbourg and Marseille.

RESULTS

Forty-eight patients were included with 27 men, hypopituitarism in 33.3% of all patients and mean serum prolactin (PRL) level at diagnosis 2218.2±4154.7μg/L. Among the patients, 58.3% received medical treatment, 25% had additional surgery and 12.5% surgery and radiotherapy. The mean follow-up duration was 196±100 months. At the end of follow-up, 10 patients (20.8%) were cured (i.e. normal PRL level and normal imaging, no symptoms and withdrawal of DA≥1 year), 33 (68.8%) were controlled (i.e. normal PRL level, normal or abnormal imaging, no symptoms, DA in progress) and 5 (10.4%) were uncontrolled. Uncontrolled patients had significant higher baseline PRL level (P=0.0412) and cabergoline cumulative dose (P=0.0065) compared to the controlled group. There was no increase in frequency of hypopituitarism. Clinically significant valvular heart disease was found in 2 patients but screening was not systematic.

CONCLUSIONS

Macroprolactinoma is currently most often a chronic disease controlled with DA. However, uncertainty about the adverse effects associated with high cumulative doses and the lack of data on the prognosis at very long-term should incite to revisit current strategies, including the role of surgery combined to medical treatment.

Gender differences in macroprolactinomas: a single centre experience

Macroprolactinomas are the most common functional pituitary tumours. Hypotheses proposed to explain predominance of large tumours in males are: i) diagnostic delay, as hyperprolactinaemia remains under recognised in males and ii) gender-specific difference in tumour proliferation indices. Our study objectives are to compare gender differences in clinical, biochemical, radiological features, management outcomes and cabergoline responsiveness in macroprolactinomas. Drug resistance was defined as failure to achieve prolactin normalisation and >50% reduction in tumour volume with cabergoline (3.5 mg/week dose for minimum 6 months duration). The baseline characteristics of 100 patients (56 females and 44 males) with macroprolactinoma were analysed. Drug responsiveness was analysed in 88 treatment naive patients, excluding 12 post-primary trans-sphenoidal surgery cases. We found that females (30.29±10.39 years) presented at younger mean age than males (35.23±9.91 years) (P<0.01). The most common presenting symptom was hypogonadism (oligo-amenorrhoea/infertility) in females (96.15%) and symptoms of mass effect (headache and visual field defects) in males (93.18%). Baseline mean prolactin levels were significantly lower in females (3094.36±6863.01 ng/ml) than males (7927.07±16 748.1 ng/ml) (P<0.001). Maximal tumour dimension in females (2.49±1.48 cm) was smaller than males (3.93±1.53 cm) (P<0.001). In 88 treatment naïve patients, 27.77% females and 35.29% males had resistant tumours (P=0.48). On subgrouping as per maximum tumour dimension (1.1-2 cm, 2.1-4 cm and >4 cm), gender difference in response rate was insignificant. In conclusion, macroprolactinomas are equally prevalent in both sexes. Macroprolactinomas in males predominantly present with symptoms of mass effects, as against females who present with symptoms of hypogonadism. Males harbor larger tumours but are equally cabergoline responsive as those in females.

Management of macroprolactinomas

Prolactin (PRL) secreting tumors are the most common functional neoplasms of the pituitary and are commonly subdivided into microprolactinomas (<10 mm) and macroprolactinomas (≥10 mm) according to their baseline diameter. Patients with prolactinoma present with symptoms evolving from hyperprolactinemia and with those caused by pressure of the expanding mass on surrounding tissues, including the optic chiasm and the cavernous sinuses. We hereby describe the possible complications of macroprolactinomas, including mass effects, hypopituitarism, CSF leak and apoplexy and discuss their relevant management.

In general, all patients harboring macroprolactinomas should be treated, the objectives being to achieve normal or near normal PRL levels, to reduce or stabilize adenoma size and to recover altered pituitary axes. Medical therapy with dopamine agonists (DA) is the preferred initial treatment for the vast majority of patients harboring prolactinomas. Pituitary surgery is indicated in patients who cannot tolerate or are resistant to therapy with DAs, patients that seek fertility and harbor adenomas that impinge on the optic chiasm, psychiatric patients with contraindication to DA treatment and patients presenting with pituitary apoplexy or a cerebrospinal fluid (CSF) leak. In addition, in this review, several patient populations with unique clinical characteristics will be discussed separately namely postmenopausal women, the elderly, children and patients with pituitary carcinoma.

Hypopituitarism patterns and prevalence among men with macroprolactinomas

PURPOSE

Men with prolactin-secreting tumors usually harbor macroadenomas. The degree of pituitary dysfunction may vary among different adenoma size subgroups, as is recovery after treatment. Our study purpose was to characterize hypopituitarism and recovery after treatment in men with macroprolactinomas.

METHODS

A retrospective study, including a consecutive group of 81 men with pituitary macroadenomas (≥10 mm) and hyperprolactinemia (>7×ULN). Patients were divided into three categories according to adenoma size at presentation: 10-19 mm (group A), 20-39 mm (group B), and ≥40 mm (group C). We compared total testosterone, gonadotropins, cortisol, thyroid hormones and hemoglobin levels at presentation and after treatment.

RESULTS

Eighty-one patients were included; 24, 31 and 26 patients in groups A, B and C, respectively. Pretreatment hypogonadism prevalence was 75.0, 93.5 and 90.9% (p = 0.046; A vs B and C), central hypocortisolism - 0, 6.9 and 33.3% (p = 0.005), and central hypothyroidism - 6.7, 17.9 and 26.1% (NS) in groups A, B and C, respectively. Only 26.7% of all patients presented with hypocortisolism and/or hypothyroidism (42.9% in group C). Anemia (Hb < 13.5 g%) was detected in 31.3, 57.1 and 80.0% in groups A, B and C, respectively (p = 0.04). Larger adenoma diameter correlated strongly with lower FT4 levels following treatment (r = -0.42, p = 0.043).

CONCLUSIONS

Macroprolactinomas in men caused partial hypopituitarism, affecting testosterone in all adenoma size groups and cortisol more in patients with larger adenomas. However, most of the men did not have pituitary hormones affected, beside testosterone. Most patients recovered central hypocortisolism but not hypothyroidism following treatment.