First-line surgery in prolactinomas: lessons from a long-term follow-up study in a tertiary referral center

Clinical Characteristics and Outcomes of Prolactinomas in Children and Adolescents: A Large Retrospective Cohort Study

CONTEXT

Prolactinoma, the most common subtype of pituitary adenoma, is rare in children and adolescents. Clinical presentation and treatment outcomes of prolactinomas in this population have been evaluated insufficiently.

OBJECTIVE

To summarize the clinical features, both medication and surgical outcomes of prolactinomas in children and adolescents in a large retrospective cohort from China.

METHODS

A cohort of patients with prolactinomas aged ≤20 years at diagnosis between 2012 and 2021 in Peking Union Medical College Hospital were retrospectively analyzed.

RESULTS

The cohort comprised 170 patients (115 females and 55 males, median age 16.6 years), with 20.0% (23/115) girls without menarche and 33.3% (18/54) boys in prepuberty. The median maximal diameter was 15.0 mm (61.2% macroadenomas and 4.6% giant adenomas), and the median baseline prolactin (PRL) level was 211.0 ng/mL. Larger sizes and higher PRL levels were observed in girls without menarche at diagnosis and in boys. Most girls presented with menstrual disturbance (86.7%), and boys were frequently bothered by headaches (42.6%), reduced height velocities (25.9%), and delayed puberty (18.2%). Dopamine agonists (DAs) were used as first-line treatment in 133 patients, and the resistance rate was 22.5% (25/111), independently associated with maximal tumor diameters (P = .035). Surgery was performed in 76 patients. Long-term surgical remission rates were 32.9% (25/76) overall, negatively associated with cavernous sinus invasion independently (P = .025), 59.4% (19/32) in noninvasive tumors (64.0% in 25 noninvasive macroadenomas), and 5.0% (1/20) in invasive tumors.

CONCLUSION

Pediatric prolactinomas exhibited more severe clinical characteristics in boys and in patients diagnosed during earlier stages of pubertal developments. Given the overall efficacy of PRL normalization by medication and considerable surgical remission rate in noninvasive tumors, DAs remain the first-line recommendation for prolactinomas in children and adolescents, while surgery might be viable for noninvasive tumors.

Characteristics and outcomes of men with erectile dysfunction as the presenting symptom due to a lactotroph adenoma

PURPOSE

Erectile dysfunction (ED) is frequently underreported in men suffering from prolactinomas and can be challenging to manage. Both dopamine agonists (DAs) and transsphenoidal surgery (TSS) correct hyperprolactinemia and restore gonadal function. However, there is scarce data regarding their effectiveness in correcting ED over the long term.

METHODS

This study is a retrospective single-center comparative cohort study analyzing men diagnosed with prolactinomas, both with and without confirmed erectile dysfunction (ED) at diagnosis. Independent risk factors for persistent ED over the long term were examined using multivariate logistic regression.

RESULTS

Among the 39 men with lactotroph adenomas, ED was one of the presenting symptoms in 22 (56%). The mean age at diagnosis was 45 ± 12 years. Surgery was the primary treatment in 6 (27%) ED patients and 8 (47%) non-ED patients. After a mean follow-up of 74 ± 48 months, remission from hyperprolactinemia was achieved in the majority (76%) of men: 71% in the non-ED cohort and 81% in the ED group (p = 0.70), regardless of the primary treatment strategy (surgical 84% versus medical 72%, p = 0.46). Long-term remission of ED was noted in 16 (73%) patients. Interestingly, high baseline BMI levels emerged as potential risk factors for persistent ED over the long term (OR 1.4, 95%CI 1.0-1.9; p = 0.04), while neither the initial adenoma size nor the primary treatment strategy (i.e., TSS vs. DAs) reached statistical significance.

CONCLUSIONS

Correcting hyperprolactinemia and its associated hypogonadism significantly improves ED in the majority of men with prolactinomas over the long term, regardless of the primary treatment strategy employed. In addition to addressing endocrine deficiencies, the early initiation of weight control programs may be considered for men with lactotroph adenomas and ED. Although our study suggests an association between BMI and the risk of persistent ED, further research is needed to establish any causal relationships.

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.

Morbidities and mortality among hospitalized patients with hypopituitarism: Prevalence, causes and management

Hypopituitarism is a highly heterogeneous multisystem disorder that can have a major impact on long-term morbidity and mortality, but even more so during acute medical conditions requiring hospitalization. Recent studies suggest a significant in-hospital burden with prolonged length of stay, increased rate of intensive care unit (ICU) admission, and initiation of mechanical ventilation - all of which may lead to an increased risk of in-hospital mortality. On the one hand, patients with hypopituitarism are often burdened by metabolic complications, including obesity, hypertension, dyslipidemia, and hyperglycemia, which alone, or in combination, are known to significantly alter relevant physiological mechanisms, including metabolism, innate and adaptive immune responses, coagulation, and wound healing, thereby contributing to adverse in-hospital outcomes. On the other hand, depending on the extent and the number of pituitary hormone deficiencies, early recognition of hormone deficiencies and appropriate management and replacement strategy within a well-organized multidisciplinary team are even stronger determinants of short-term outcomes during acute hospitalization in this vulnerable patient population. This review aims to provide an up-to-date summary of recent advances in pathophysiologic understanding, clinical implications, and recommendations for optimized multidisciplinary management of hospitalized patients with hypopituitarism.

The diagnostic yield of inferior petrosal sinus sampling in Cushing syndrome in the era of ovine CRH shortage

PURPOSE

The ovine corticotropin-releasing hormone (oCRH) stimulation test has been routinely used in the diagnostic work-up of ACTH-dependent Cushing syndrome (CS). With oCRH currently being out-of-stock in Europe, we aimed at evaluating the diagnostic performance of inferior petrosal sinus sampling (IPSS) without oCRH stimulation.

METHODS

We compared the values of 40 patients with ACTH-dependent CS and negative MRI findings in whom ACTH was measured before and after oCRH stimulation.

RESULTS

The ratio of central-to-peripheral ACTH measurement (IPS:P) before the combined 3, 5, and 10 min of oCRH stimulation yielded diminished sensitivity (85% vs. 97%), alongside markedly decreased specificity (57% vs. 71%), as well as reduced positive and negative predictive values (90% vs. 94% and 44% vs. 83%), respectively.

CONCLUSIONS

With the current drug shortages in Europe, ACTH measurements without oCRH stimulation in IPSS cannot be recommended. Thus, we call for desmopressin or the commercially available human CRH as a potential alternative in the confirmation of ACTH excess by IPSS in equivocal MRI findings.

The Effect of Preoperative Cabergoline on Prolactinoma Fibrosis: A Case Series

Introduction  Prolactinomas are a common intracranial neoplasm and constitute most pituitary tumors. Although patients can present with variable hormone dysregulation and symptom severity, the use of dopamine agonists remains a first-line treatment. While bromocriptine has been found to increase tumor fibrosis, the effect of cabergoline on collagen deposition has been disputed. The aim of this article is to understand the influence of cabergoline on tumor fibrosis prior to resection. Case Presentations  Four male patients who underwent prolactinoma resection were included in this report. The average age was 39.8 years (range: 26-52 years). Pre-treatment prolactin levels ranged from 957.8 to 16,487.4 ng/mL. Three patients received cabergoline for at least 1 month prior to surgery (treatment range: 1-6 months). One patient had surgery without prior cabergoline use. Pathology reports confirmed each tumor to be of lactotroph origin. For each sample, Masson's trichrome staining was performed and the percentage of sample fibrosis was quantified using an artificial intelligence imaging software. Among those who received preoperative cabergoline, the extent of tumor fibrosis was in the range of 50 to 70%. In contrast, specimen fibrosis was approximately 15% without cabergoline use. Conclusion  This report demonstrates that a short duration of preoperative cabergoline can cause significant prolactinoma fibrosis. Understanding the effect of cabergoline on tumor consistency prior to surgery is essential as increased fibrosis can lead to more difficult tumor removal, reduce the extent of resection, and increase surgical complications. Considering these effects, further studies regarding the use of surgery prior to cabergoline for prolactinoma management are warranted.

Efficacy and Safety of Endoscopic Transsphenoidal Resection for Prolactinoma: A Retrospective Multicenter Case-series

BACKGROUND

Endoscopic transsphenoidal surgery (ETSS) for prolactinoma is reserved for dopamine agonist (DA) resistance, intolerance, or apoplexy. High remission (overall 67%, microprolactinoma up to 90%), low recurrence (5-20%) rates highlighted that surgery might be first-line treatment.

AIMS

To report on outcomes of ETSS in a cohort of prolactinomas.

METHODS

Multicenter retrospective cohort of 137 prolactinoma patients (age 38.2 ± 13.7 years; 61.3% female, median follow-up 28.0 [15.0-55.5] months) operated between 2010-2019 with histopathological confirmation.

RESULTS

Median preoperative prolactin levels were 166 (98-837 µg/L; males 996 [159-2145 µg/L] vs. females 129 [84-223 µg/L], p <0.001). 56 (40.9%) microprolactinomas, 69 (50.4%) macroprolactinomas, and 7 (5.1%) giant prolactinomas were included, whereas no adenoma was detected in 5 (3.6%) patients. Males had larger tumors (macroprolactinomas: 38, 71.7%) vs. 31 (36.9%), p <0.001; giant prolactinomas: 7 (13.2%) vs. 0 (0.0%), (p <0.001). Prolactinomas were graded as KNOSP-3 in 15 (11.5%), and KNOSP-4 in 20 (15.3%) patients. Primary indication was DA intolerance (59, 43.1%); males 14 (26.4%) vs. females 45 (53.6%), p = 0.006. Long-term remission (i.e., DA-free prolactin level <1xULN) was achieved in 87 (63.5%) patients, being higher in intended complete resection (69/92 [75.0%]), and lower in males (25 [47.2%] vs. 62 females [73.8%], p = 0.002). Transient DI (n = 29, 21.2%) was the most frequent complication.

CONCLUSIONS

Despite high proportions of macroprolactinoma and KNOSP 3-4, long-term remission rates were 63.5% overall, and 83.3% in microprolactinoma patients. Males had less favorable remission rate compared to females. These findings highlight that ETSS may be a safe and efficacious treatment to manage prolactinoma.

Outcomes of Endoscopic Transsphenoidal Approach for More Aggressive Pediatric Pituitary Adenomas: Early- and Late-Term Results from a Single Center Experience

OBJECTIVE

Pediatric pituitary adenomas are rare lesions and account for approximately 3% of all supratentorial tumors in children. There is a paucity of reports on endoscopic transsphenoidal surgery in children. The aim of this study was to assess the early/late outcomes of endoscopic pediatric pituitary adenoma surgery at a high-volume tertiary center, as well as to characterize the factors associated with aggressive growth, including the histopathological features.

METHODS

Between August 1997 and June 2022, a total of 3256 patients underwent endoscopic transsphenoidal surgery for pituitary adenoma at the Department of Neurosurgery and Pituitary Research Center of the Kocaeli University School of Medicine. Of these, 70 (2.1%) pediatric patients (25 males, 45 females) (age ≤18 years) with a pathological diagnosis of pituitary adenoma were retrospectively reviewed.

RESULTS

The mean age of patients was 15.5 ± 2.3 years. Among the hormone-secreting adenomas, 19 (34.5%) were adrenocorticotrophic hormone secreting, 13 (23.6%) were growth hormone secreting, 19 (34.5%) were prolactin secreting, and 4 (7.2%) were both growth hormone-prolactin secreting. Gross total resection was achieved in 93.3% of nonfunctional tumors. The early/late surgical remission rates for hormone-secreting adenomas were 61.5%/46.1% (mean follow-up: 63.7 ± 49.3 months) for acromegaly, 78.9%/68.4% (47.8 ± 51.0 months) for Cushing disease, 57.8%/31.5% (72.2 ± 59.5 months) for prolactinoma, and 25%/25% (35.2 ± 31.4 months) for growth hormone-prolactin-secreting adenomas. Five sparsely granulated corticotroph tumors, 5 sparsely granulated somatotroph tumors, and 11 densely granulated lactotroph tumors were classified as aggressive histopathological subtypes.

CONCLUSIONS

The unique characteristics of the pediatric population and the aggressiveness of the disease in this population pose considerable therapeutic challenges. To increase treatment success, current adjuvant therapies that are appropriate for the morphological and biological characteristics of the tumor are required in addition to surgical treatment.

Prolactinomas in adolescent and elderly patients-A comparative long-term analysis

Objectives

Prolactinomas represent the most common type of secreting pituitary adenomas, yet are rarely encountered in adolescent-onset (AO; i.e. <18 years) or elderly-onset (EO; i.e. ≥65 years) cohorts. As a result, it is not clear whether long-term strategies should be focused differently at both age extremes when comparing their therapeutic outcomes. We aimed at investigating long-term endocrinological outcomes, looking for differences between the two cohorts and evaluating the dependence on continued dopamine agonist (DA) therapy.

Methods

Retrospective cross-sectional comparative study analyzing prolactinoma patients with a follow-up of ≥4 years. Clinical, radiological and biochemical characteristics were assessed at diagnosis and last follow-up. Longitudinal endocrinological outcomes between groups of extreme ages (i.e. AO and EO) and middle age (i.e. ≥18 years to 65 years) were compared. Independent risk factors for long-term dependence on DAs were calculated.

Results

Follow-up at ≥4 years was recorded for 108 prolactinoma patients; 10 patients with AO and 10 patients with EO. Compared to AO patients, EO patients were predominantly men (p = 0.003), and presented with significantly higher prolactin (PRL) levels (p = 0.05) and higher body mass index (p = 0.03). We noted a significant positive correlation between patients' PRL values and their age (r = 0.5, p = 0.03) or BMI (r = 0.6, p = 0.03). After a median follow-up of 115 months, remission was noted in 87 (83%) patients; 9 (90%) in AO patients, and 7 (70%) in EO patients (p = 0.58). Continuation of DAs was required in 4 patients (40%) with AO and 7 patients (70%) with EO (p = 0.37). Patients with elderly-onset were an independent predictor of long-term dependence on DAs (HR 2.8, 95% CI 1.1-7.2, p = 0.03).

Conclusions

Long-term control of hyperprolactinemia and hypogonadism does not differ between members of the AO and EO cohorts, and can be attained by the majority of patients. However, adjuvant DAs are often required, independent of the age of onset. Considering the clinical significance of persistent DA therapy for the control of hyperprolactinemia in many patients at both extremes of age, long-term monitoring may become recommended, in particular in patients with elderly-onset.

Surgical Management of Giant Prolactinomas: A Descriptive Study

Introduction

Giant prolactinoma (GP) is a rare pituitary lactotropic cell tumor larger than 4 cm in its widest dimension, and is less likely than a smaller prolactinoma to achieve prolactin normalization on dopamine agonist (DA) monotherapy. There is a paucity of data on the circumstances and outcomes of second-line management of GP with surgery. Herein, our institution's experience with the surgical management of GPs is described.

Methods

A single-center retrospective analysis was conducted of patients who underwent surgery for giant prolactinoma from 2003 to 2018. A chart review was conducted for demographic data, clinical features, laboratory and radiographic findings, operative and pathology reports, perioperative management, and clinical outcomes in follow-up. Descriptive statistics were used.

Results

Of 79 prolactinoma cases, 8 patients had GP with a median age of 38 years (range 20-53), 75% (6/8) were male, with a median largest tumor dimension of 6 cm (range 4.6-7.7), and a median prolactin level of 2,500 μg/L (range 100->13,000). Six patients had transsphenoidal surgery for dopamine agonist (DA) resistance or intolerance. Two patients had a craniotomy for a missed diagnosis; one was due to the hook effect. No tumor resections were complete by either surgical approach; all had persistent hyperprolactinemia requiring postoperative DA therapy, and two patients had an additional craniotomy procedure for further tumor debulking. There was no recovery of pituitary axes and postoperative deficits were common. Remission as defined by prolactin normalization occurred in 63% (5/8) at a median time of 36 months (range 14-63 months) on DA therapy after surgery with a follow-up of 3-13 years.

Conclusions

GPs infrequently require surgical resection, which is generally incomplete and requires adjuvant therapy. Given the rarity of surgery for GPs, multi-institutional or registry studies would yield clearer guidance on optimal management.

Treatment of Prolactinoma

Prolactinomas are the commonest form of pituitary neuroendocrine tumor (PitNET), representing approximately half of such tumors. Dopamine agonists (DAs) have traditionally been the primary treatment for the majority of prolactinomas, with surgery considered the second line. The aim of this review is to examine the historical and modern management of prolactinomas, including medical therapy with DAs, transsphenoidal surgery, and multimodality therapy for the treatment of aggressive prolactinomas and metastatic PitNETs, with an emphasis on the efficacy, safety, and future directions of current therapeutic modalities. DAs have been the mainstay of prolactinoma management since the 1970s, initially with bromocriptine and more recently with cabergoline. Cabergoline normalizes prolactin in up to 85% of patients and causes tumor shrinkage in up to 80%. Primary surgical resection of microprolactinomas and enclosed macroprolactinomas performed by experienced pituitary neurosurgeons have similar remission rates to cabergoline. Aggressive prolactinomas and metastatic PitNETS should receive multimodality therapy including high dose cabergoline, surgery, radiation therapy (preferably using stereotactic radiosurgery where suitable), and temozolomide. DAs remain a reliable mode of therapy for most prolactinomas but results from transsphenoidal surgery in expert hands have improved considerably over the last one to two decades. Surgery should be strongly considered as primary therapy, particularly in the setting of microprolactinomas, non-invasive macroprolactinomas, or prior to attempting pregnancy, and has an important role in the management of DA resistant and aggressive prolactinomas.

Clinical and radiological presentation of parasellar ectopic pituitary adenomas: case series and systematic review of the literature

PURPOSE

Parasellar ectopic pituitary adenomas (pEPAs) are extremely rare tumors located out of the sella turcica. PEPAs are heterogeneous entities in terms of anatomical localization and secretion of anterior pituitary hormones.

METHODS

Multicenter retrospective study. Clinical charts' consultation of patients diagnosed with parasellar lesions, to identify all subjects fulfilling the diagnostic criteria of parasellar EPAs. Systematic review of the literature focused on the medical management of prolactin-secreting pEPAs and on the prevalence of radiological bone invasion in pEPAs.

RESULTS

We identified four cases of pEPAs: (1) 54-year-old female with a prolactin-secreting suprasellar EPA successfully treated with cabergoline; (2) 74-year-old male with a non-functioning EPA of the sphenoidal sinus treated with endoscopic transsphenoidal surgery; (3) 75-year-old female with a giant lesion of the skull base (maximum diameter 7.2 cm) diagnosed as a non-functioning EPA after biopsy; (4) 49-year-old male with a silent corticotroph EPA of the sphenoidal sinus and clivus. Three out of four cases had radiological evidence of invasion of the surrounding bone structures. A systematic review of the literature highlighted that medical therapy can be effective in prolactin-secreting pEPAs. Overall, we found mention of local invasiveness in 65/147 cases (44.2%), confirmed by radiological signs of bone invasion/erosion.

CONCLUSION

Our experience confirms the heterogeneity of pEPAs in terms of clinical and radiological presentation, as well as hormone secretion. PEPAs show a high frequency of radiological bone invasion, though similar to that of sellar pituitary adenomas. Although extremely rare, pEPAs need to be considered in the differential diagnosis of parasellar lesions.

11C-methionine PET aids localization of microprolactinomas in patients with intolerance or resistance to dopamine agonist therapy

PURPOSE

To assess the potential for ¹¹C-methionine PET (Met-PET) coregistered with volumetric magnetic resonance imaging (Met-PET/MR^CR) to inform clinical decision making in patients with poorly visualized or occult microprolactinomas and dopamine agonist intolerance or resistance.

PATIENTS AND METHODS

Thirteen patients with pituitary microprolactinomas, and who were intolerant (n = 11) or resistant (n = 2) to dopamine agonist therapy, were referred to our specialist pituitary centre for Met-PET/MR^CR between 2016 and 2020. All patients had persistent hyperprolactinemia and were being considered for surgical intervention, but standard clinical MRI had shown either no visible adenoma or equivocal appearances.

RESULTS

In all 13 patients Met-PET/MR^CR demonstrated a single focus of avid tracer uptake. This was localized either to the right or left side of the sella in 12 subjects. In one patient, who had previously undergone surgery for a left-sided adenoma, recurrent tumor was unexpectedly identified in the left cavernous sinus. Five patients underwent endoscopic transsphenoidal selective adenomectomy, with subsequent complete remission of hyperprolactinaemia and normalization of other pituitary function; three patients are awaiting surgery. In the patient with inoperable cavernous sinus disease PET-guided stereotactic radiosurgery (SRS) was performed with subsequent near-normalization of serum prolactin. Two patients elected for a further trial of medical therapy, while two declined surgery or radiotherapy and chose to remain off medical treatment.

CONCLUSIONS

In patients with dopamine agonist intolerance or resistance, and indeterminate pituitary MRI, molecular (functional) imaging with Met-PET/MR^CR can allow precise localization of a microprolactinoma to facilitate selective surgical adenomectomy or SRS.

Implementation of functional imaging using 11C-methionine PET-CT co-registered with MRI for advanced surgical planning and decision making in prolactinoma surgery

PURPOSE

To report the first experience of our multidisciplinary team with functional imaging using ¹¹C-methionine positron emission tomography-computed tomography (¹¹C-methionine PET-CT) co-registered with MRI (Met-PET/MRI^CR) in clinical decision making and surgical planning of patients with difficult to treat prolactinoma.

METHODS

In eighteen patients with prolactinoma, referred to our tertiary referral centre because of intolerance or resistance for dopamine agonists (DA), Met-PET/MRI^CR was used to aid decision-making regarding therapy.

RESULTS

Met-PET/MRI^CR was positive in 94% of the patients. MRI and Met-PET/MRI^CR findings were completely concordant in five patients, partially concordant in nine patients, and non-concordant in four patients. In five patients Met-PET/MRI^CR identified lesion(s) that were retrospectively also visible on MRI. Met-PET/MRI^CR was false negative in one patient, with a cystic adenoma on conventional MRI. Thirteen patients underwent transsphenoidal surgery, with nine achieving full biochemical remission, two clinical improvement and near normalized prolactin levels, and one patient clinical improvement with significant tumour reduction. Hence, nearly all patients (94%) were considered to have a positive outcome. Permanent complication rate was low. Three patients continued DA, two patients have a wait and scan policy.

CONCLUSION

Met-PET/MRI^CR can provide additional information to guide multidisciplinary preoperative and intraoperative decision making in selected cases of prolactinoma. This approach resulted in a high remission rate with a low rate of complications in our expert centre.

Update in Pathogenesis, Diagnosis, and Therapy of Prolactinoma

Simple Summary

This review updates recent advances in the pathogenesis, diagnosis, and therapy of prolactinoma. Prolactinomas, comprising 30–50% of all pituitary neuroendocrine tumors, frequently occur in females aged 20 to 50 and cause hypogonadism and infertility. In typical cases, female patients exhibit galactorrhea and amenorrhea due to serum prolactin (PRL) elevation, and during pregnancy, they should be carefully treated. During diagnosis, other causes of hyperprolactinemia must be excluded, and an MRI is useful for detecting pituitary neuroendocrine tumors. For the treatment of prolactinoma, dopamine agonists are effective in decreasing PRL levels and shrinking tumor size in most patients. Surgical treatment is recommended for patients who are resistant or intolerant to dopamine agonists. This review also discusses giant and malignant prolactinomas, prolactinoma-associated pregnancy, and new therapeutic approaches.

Abstract

Prolactinomas comprise 30–50% of all pituitary neuroendocrine tumors, frequently occur in females aged 20 to 50, and cause hypogonadism and infertility. In typical cases, female patients exhibit galactorrhea and amenorrhea due to serum prolactin (PRL) elevation, and patients during pregnancy should be carefully treated. During diagnosis, other causes of hyperprolactinemia must be excluded, and an MRI is useful for detecting pituitary neuroendocrine tumors. For treating prolactinoma, dopamine agonists (DAs) are effective for decreasing PRL levels and shrinking tumor size in most patients. Some DA-resistant cases and the molecular mechanisms of resistance to a DA are partially clarified. The side effects of a DA include cardiac valve alterations and impulse control disorders. Although surgical therapies are invasive, recent analysis shows that long-term remission rates are higher than from medical therapies. The treatments for giant or malignant prolactinomas are challenging, and the combination of medication, surgery, and radiation therapy should be considered. Regarding pathogenesis, somatic SF3B1 mutations were recently identified even though molecular mechanisms in most cases of prolactinoma have not been elucidated. To understand the pathogenesis of prolactinomas, the development of new therapeutic approaches for treatment-resistant patients is expected. This review updates the recent advances in understanding the pathogenesis, diagnosis, and therapy of prolactinoma.

Extra-Pseudocapsular Transsphenoidal Surgery for Microprolactinoma in Women

A recall for histological pseudocapsule (PS) and reappraisal of transsphenoidal surgery (TSS) as a viable alternative to dopamine agonists in the treatment algorithm of prolactinomas are getting vibrant. We hope to investigate the effectiveness and risks of extra-pseudocapsular transsphenoidal surgery (EPTSS) for young women with microprolactinoma, and to look into the factors that influenced remission and recurrence, and thus to figure out the possible indication shift for primary TSS. We proposed a new classification method of microprolactinoma based on the relationship between tumor and pituitary position, which can be divided into hypo-pituitary, para-pituitary and supra-pituitary groups. We retrospectively analyzed 133 patients of women (<50 yr) with microprolactinoma (≤10 mm) who underwent EPTSS in a tertiary center. PS were identified in 113 (84.96%) microadenomas intraoperatively. The long-term surgical cure rate was 88.2%, and the comprehensive remission rate was 95.8% in total. There was no severe or permanent complication, and the surgical morbidity rate was 4.5%. The recurrence rate with over 5 years of follow-up was 9.2%, and a lot lower for the tumors in the complete PS group (0) and hypo-pituitary group (2.1%). Use of the extra-pseudocapsule dissection in microprolactinoma resulted in a good chance of increasing the surgical remission without increasing the risk of CSF leakage or endocrine deficits. First-line EPTSS may offer a greater opportunity of long-term cure for young female patients with microprolactinoma of hypo-pituitary located and Knosp grade 0-II.

Dopamine agonist therapy for prolactinomas: do we need to rethink the place of surgery in prolactinoma management?

The current treatment paradigm for prolactinomas involves dopamine agonist (DA) therapy as the first-line treatment, with surgical resection reserved for cases where there is DA failure due to resistance or intolerance. This review highlights how DA therapy can be optimised to overcome its increasingly recognised pitfalls, whilst also addressing the potential for expanding the use of surgery in the management of prolactinomas. The first part of the review discusses the limitations of DA therapy, namely: DA resistance; common DA side effects; and the rare but serious DA-induced risks of cardiac valvulopathy, impulse control disorders, psychosis, CSF rhinorrhoea and tumour fibrosis. The second part of the review explores the role of surgery in prolactinoma management with reference to its current second-line position and recent calls for surgery to be considered as an alternative first-line treatment alongside DA therapy. Randomised trials comparing medical vs surgical therapy for prolactinomas are currently underway. Pending these results, a low surgical threshold approach is herein proposed, whereby DA therapy remains the default treatment for prolactinomas unless there are specific triggers to consider surgery, including concern regarding DA side effects or risks in vulnerable patients, persistent and bothersome DA side effects, emergence of any serious risks of DA therapy, expected need for long-term DA therapy, as well as the traditional indications for surgery. This approach should optimise the use of DA therapy for those who will most benefit from it, whilst instituting surgery early in others in order to minimise the cumulative burden of prolonged DA therapy.

Machine Learning for Outcome Prediction in First-Line Surgery of Prolactinomas

BACKGROUND

First-line surgery for prolactinomas has gained increasing acceptance, but the indication still remains controversial. Thus, accurate prediction of unfavorable outcomes after upfront surgery in prolactinoma patients is critical for the triage of therapy and for interdisciplinary decision-making.

OBJECTIVE

To evaluate whether contemporary machine learning (ML) methods can facilitate this crucial prediction task in a large cohort of prolactinoma patients with first-line surgery, we investigated the performance of various classes of supervised classification algorithms. The primary endpoint was ML-applied risk prediction of long-term dopamine agonist (DA) dependency. The secondary outcome was the prediction of the early and long-term control of hyperprolactinemia.

METHODS

By jointly examining two independent performance metrics - the area under the receiver operating characteristic (AUROC) and the Matthews correlation coefficient (MCC) - in combination with a stacked super learner, we present a novel perspective on how to assess and compare the discrimination capacity of a set of binary classifiers.

RESULTS

We demonstrate that for upfront surgery in prolactinoma patients there are not a one-algorithm-fits-all solution in outcome prediction: different algorithms perform best for different time points and different outcomes parameters. In addition, ML classifiers outperform logistic regression in both performance metrics in our cohort when predicting the primary outcome at long-term follow-up and secondary outcome at early follow-up, thus provide an added benefit in risk prediction modeling. In such a setting, the stacking framework of combining the predictions of individual base learners in a so-called super learner offers great potential: the super learner exhibits very good prediction skill for the primary outcome (AUROC: mean 0.9, 95% CI: 0.92 - 1.00; MCC: 0.85, 95% CI: 0.60 - 1.00). In contrast, predicting control of hyperprolactinemia is challenging, in particular in terms of early follow-up (AUROC: 0.69, 95% CI: 0.50 - 0.83) vs. long-term follow-up (AUROC: 0.80, 95% CI: 0.58 - 0.97). It is of clinical importance that baseline prolactin levels are by far the most important outcome predictor at early follow-up, whereas remissions at 30 days dominate the ML prediction skill for DA-dependency over the long-term.

CONCLUSIONS

This study highlights the performance benefits of combining a diverse set of classification algorithms to predict the outcome of first-line surgery in prolactinoma patients. We demonstrate the added benefit of considering two performance metrics jointly to assess the discrimination capacity of a diverse set of classifiers.

Postoperative remission of non-invasive lactotroph pituitary tumor: a single-center experience

BACKGROUND

Dopaminergic agonists (DA) are the first-line treatment in lactotroph pituitary tumor but treatment usually needs to be life-long. After surgical transphenoid resection, remission rates range from 60% to 90%, with low morbidity.

OBJECTIVE

The objective was to evaluate outcome of surgical treatment of selected non-invasive prolactinoma, and to identify factors associated with long-term remission.

METHOD

Early postoperative (3 months) and last follow-up data for non-invasive lactotroph tumors operated on in intention-to-cure in our center, between 2008 and 2017 were retrospectively reviewed: prolactin (PRL) level, DA treatment, pituitary function, and MRI data. Remission was defined as PRL plasma level below the upper limit of normal without DA treatment.

RESULTS

Fifty-three of the 60 patients (32 of the 33 microadenomas) were in remission at 3 months and 46 (28/33 microadenomas) at last follow-up 22.7 months (range, 1.1-126.5 months) after surgery. Five-year recurrence-free survival was 77.5% [65.8-91.2]. Male gender, larger tumor size at diagnosis and before surgery and higher plasma PRL level at diagnosis were all significantly associated with lower remission rates on univariate analysis. Transient diabetes insipidus and hyponatremia occurred in 2 and 5 patients respectively. One case of isolated thyrotroph insufficiency was observed. During follow-up, 13 women became pregnant (12 spontaneously).

CONCLUSION

This cohort confirmed the high remission rate of lactotroph tumors after surgery in a selected population, with limited morbidity, and conserved pituitary function in almost all cases.

Surgery is a safe, effective first-line treatment modality for noninvasive prolactinomas

PURPOSE

Dopamine agonists (DAs) have long been the recommended first-line treatment for prolactinoma. Given the remarkable developments in surgical techniques, however, surgery is on the rise. We compared the treatment outcomes of patients with noninvasive prolactinomas receiving two different initial treatments (DAs and transsphenoidal surgery).

METHODS

We reviewed 745 patients with hyperprolactinemia or pituitary tumors treated from 2004 to 2020 at Chonnam National University Hwasun Hospital and identified 310 with prolactinomas. After selecting patients who had pituitary tumors with Knosp grade 0 to 1 with follow-up period over 1 year, 70 patients (29 who underwent surgery and 41 who received DAs as the initial treatment) were finally included for a comparative study.

RESULTS

The surgery group exhibited better outcomes in terms of DA-free remission and the structural response, although the tumor size was significantly larger than in the DA group. The groups exhibited comparable results in terms of symptom control and the biochemical response. Univariate and multivariate analyses indicated that surgery as the initial treatment modality provided significantly better clinical outcomes in terms of DA-free remission. In the surgery group, a postoperative prolactin level < 10 ng/mL was the only significant predictor of DA-free remission.

CONCLUSIONS

Transsphenoidal surgery showed comparable clinical outcomes in patients with prolactinomas, and low complication rates. The decision regarding the first-line treatment modality for non-invasive prolactinomas should be made on an individual basis.

Impact of primary medical or surgical therapy on prolactinoma patients' BMI and metabolic profile over the long-term

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High prolactin (PRL) levels are associated with weight gain and impaired metabolic profiles.

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Long-term control of hyperprolactinemia can be attained by first-line surgery and medical therapy.

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Normalization of PRL improves patients’ BMI and fasting glucose levels.

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Marginal changes in patients’ metabolic profiles are noted regardless of the primary therapy.

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Not dopamine agonists per se, but rather the control of hyperprolactinemia plays a role in metabolic profile alterations.

Objectives

High prolactin levels have been associated with weight gain and impaired metabolic profiles. While treatment with dopamine agonists (DAs) has been shown to improve these parameters, there is a lack of surgical series on its comparative effect in prolactinoma patients.

Methods

In this retrospective, comparative study, consecutive patients with a prolactinoma were enrolled if treated with first-line transsphenoidal surgery (TSS) or with DAs. Patients with prolactinomas of Knosp grade >2 and those with a follow-up <24 months were excluded, as were patients with missing laboratory metabolic parameters at baseline and over the long-term. Effects of either treatment on BMI and the metabolic profile were analyzed, and independent risk factors for long-term obesity were calculated.

Results

Primary treatment was TSS for 12 patients (40%) and DAs for 18 patients (60%). At diagnosis, no significant differences between the two cohorts were observed with regard to adenoma size, Knosp grading, baseline prolactin (PRL) levels, prevalence of hypogonadism, or laboratory metabolic parameters. Mean follow-up was 51.9 months (range, 24–158). Over the long-term, both TSS and DAs led to the control of hyperprolactinemia (92% vs. 72%) and hypogonadism (78% vs. 83%) in the majority of patients. While a significant decrease in patients’ BMI and fasting glucose were observed, changes in the lipid profile were marginal and independent of the treatment modality. At baseline, increased BMI—but not the primary treatment strategy—was an independent predictor of long-term obesity.

Conclusions

Over the long-term, patients’ BMI and FG improve, but changes in the metabolic profile are marginal and independent of the primary treatment. It is presumable that not DAs per se, but rather the control of hyperprolactinemia plays a role in patients’ metabolic profile alterations.