Surgery for Prolactinomas to Date

The Role of Endoscopic Transsphenoidal Surgery in Microprolactinomas: A Retrospective Study

OBJECTIVE

Most patients with microprolactinomas require lifetime treatment with a dopamine agonist. Many patients in our center have sought endoscopic transsphenoidal surgery as an alternative therapy.

METHODS

This study was a retrospective cohort analysis of 42 patients with microprolactinoma who underwent endoscopic transsphenoidal surgery between January 2010 and December 2023 performed by experienced neurosurgeons in our center.

RESULTS

The mean follow-up duration was 30.17 months (range, 13.00-45.40 months). The short-term (postoperative day 1) remission rate was 95.24%, and the long-term (>1-year follow-up) remission rate was 92.86%. The pattern of prolactin level changes on postoperative day 1 was significantly associated with recurrence. In the hypoprolactinemia group, all 29 patients achieved remission at the 1-year follow-up. In patients with normal prolactin levels, 10 of 11 patients achieved remission, while 1 of 11 patients had recurrence at the 1-year follow-up. In the hyperprolactinemia group, 2 of 2 patients had recurrence at the 1-year follow-up. Moreover, adenoma location was significantly associated with recurrence. In the recurrent group (3 patients), 2 patients belonged to the uncertain group, while the third patient belonged to the lateral group. The surgical complications were temporary and resolved shortly after surgery.

CONCLUSIONS

According to our findings, endoscopic transsphenoidal surgery performed on patients with microprolactinomas at advanced pituitary tumor centers could be an option with high success rates and low complications. Moreover, improving magnetic resonance imaging techniques and/or multidisciplinary team discussion before surgery for microprolactinoma could improve tumor remission after surgery.

Feasibility of Early Surgical Treatment for Adolescent Patients with Prolactinoma: A Case Report and Literature Review

Background and Objectives: Prolactinomas are the most common pituitary adenomas, comprising 30-50% of such tumors. These adenomas cause hyperprolactinemia, leading to decreased fertility, reduced energy and libido, and galactorrhea. Diagnosing and treating prolactinomas in adolescents present unique challenges, as symptoms may be confused with age-related developmental variations. This case report explores the outcomes of early surgical intervention in an adolescent with a prolactinoma. Materials and Methods: A 14-year-old female presented delayed menarche and absent pubertal development. Initial evaluation revealed hyperprolactinemia (228.37 ng/mL) with normal estradiol levels. Initial management through observation was adopted, but persistent amenorrhea and severe headaches prompted further investigation. Magnetic resonance imaging revealed a cystic pituitary mass with apoplexy. Due to concerns regarding delayed puberty and the need for rapid normalization of prolactin levels, the patient underwent transsphenoidal surgery. Results: After operation, prolactin levels normalized, menarche occurred within three months, and secondary sexual characteristics developed within eight months. Pathology confirmed a pituitary adenoma with a high Ki-67 index (15%). Conclusions: Early surgical intervention for prolactinomas in adolescents can achieve successful biochemical remission and resolution of endocrine symptoms. Adolescents, particularly those with a high Ki-67 index and potential resistance to dopamine agonists, may benefit from prompt surgical management, resulting in improved clinical outcomes and complete tumor resection.

No unfavorable effects on the menstruation recovery of early postoperative hypoprolactinemia after transsphenoidal surgery in patients with lactotroph pituitary neuroendocrine tumor

OBJECTIVE

Transsphenoidal surgery for lactotroph pituitary neuroendocrine tumor (PitNET) lowers serum prolactin concentrations, occasionally below the normal range. However, the clinical significance of postoperative hypoprolactinemia is still unclear. In this study, we retrospectively reviewed the female patients with lactotroph PitNET who were treated with transsphenoidal surgery to elucidate the influence of postoperative hypoprolactinemia on regular menstruation restoration and endocrinological remission.

RESULTS

The serum prolactin levels in all thirty three participating females had decreased following surgery. Serum prolactin levels in seven patients had decreased below the lower limit of normal ranges (hypoproactinemia group) and in the remaining twenty six patients, it was within the normal range (non-hypoproractinemia group). In hypoprolactinemia group, regular menstruation was restored in all patients with only lactotroph axis deficiency. Nine patients from the non-hypoprolactinemia group experienced re-elevation of serum prolactin concentration (27%). No patient in hypoprolactinemia group experienced the relapse of hyperprolactinemia. These data suggest that early postoperative hypoprolactinemia after transsphenoidal surgery for lactotroph PitNET is not only a good predictive factor for endocrinological remission but also no unfavorable effects on regular menstruation restoration.

Medical treatment of functional pituitary adenomas, trials and tribulations

CONTEXT

Functioning pituitary adenomas (FPAs) include most frequently prolactinomas, somatotroph or corticotroph adenomas, while thyrotroph and gonadotroph adenomas are very rare. Despite their benign histological nature (aggressive tumors are rare and malignant ones exceptional), FPAs could cause significant morbidity and increased mortality due to complications associated with hormonal excess syndromes and/or mass effect leading to compression of adjacent structures. This mini review will focus on the increasing role of medical therapy in the multimodal treatment, which also includes transsphenoidal surgery (TSS) and radiotherapy.

EVIDENCE SYNTHESIS

Most patients with prolactinomas are treated only with medications, but surgery could be considered for some patients in a specialized pituitary center, if higher chances of cure. Dopamine agonists, especially cabergoline, are efficient in reducing tumor size and normalizing prolactin. TSS is the first-line treatment for all other FPAs, but most patients require complex adjuvant treatment, including a combination of therapeutic approaches. Medical therapy is the cornerstone of treatment in all patients after unsuccessful surgery or when surgery cannot be offered and includes somatostatin receptor ligands and dopamine agonists (almost all FPAs), growth hormone receptor antagonists (acromegaly), adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers (Cushing's disease). Novel medical treatments, especially for acromegaly and Cushing's disease are under research.

CONCLUSIONS

An enlarged panel of effective drugs available with increased knowledge of predictive factors for response and/or adverse effects will enhance the possibility to offer a more individualized treatment. This would not only improve disease control and prognosis, but also quality of life.

Presurgical Medical Treatment in Prolactinomas: Surgical Implications and Pathological Characteristics From 290 Cases

OBJECTIVE

To review experience regarding the treatment of prolactinomas by endoscopic endonasal surgery focusing on the association between presurgical dopamine agonist (DA) treatment and perioperative outcomes, surgical morbidities, endocrine outcomes, and pathological characteristics.

METHODS

A single-center series of 290 cases was analyzed retrospectively and clinical data were collected. Intratumoral collagen content was assessed by Masson trichrome staining.

RESULTS

Tenacious tumor consistency (27.8% vs 9.8%, P < .001) was more common in DA-pretreated patients compared with patients who underwent initial surgery. Moreover, DA-pretreated macroadenomas presented more intraoperative blood loss (200 [100-400] mL vs 175 [100-300] mL; P = .014), longer surgical duration (177 ± 95 minutes vs 154 ± 57 minutes; P = .043), and more surgical morbidities (19.4% vs 8.9%; P = .034). Additionally, DA-pretreated macroadenomas presented a higher collagen volume fraction than that of the initial surgery group (23.6 ± 2.2% vs 13.2 ± 2.1%; P = .001). Correlation analysis revealed a close correlation between collagen volume fraction and the cumulative dose of bromocriptine (BRC) in macroadenomas (r = 0.438, P < .001). Regarding endocrine outcomes, DA-pretreated microadenomas showed a lower proportion of initial remission compared with patients who underwent initial surgery (86.7% vs 100%, P = .047).

CONCLUSION

This study described increased surgical difficulty and inferior endocrine outcomes associated with tumor fibrosis secondary to presurgical BRC treatment in prolactinomas. Neurosurgeons should note that presurgical BRC treatment may render subsequent surgery more challenging.

The role of surgical management for prolactin-secreting tumors in the era of dopaminergic agonists: An international multicenter report

OBJECTIVE

First-line prolactin-secreting tumor (PST) management typically involves treatment with dopamine agonists and the role of surgery remains to be further explored. We examined the international experience of 12 neurosurgical centers to assess the patient characteristics, safety profile, and effectiveness of surgery for PST management.

METHODS

Patients surgically treated for PST from January 2017 through December 2020 were evaluated for surgical characteristics, outcomes, and safety.

RESULTS

Among 272 patients identified (65.1% female), the mean age was 38.0 ± 14.3 years. Overall, 54.4% of PST were macroadenomas. Minor complications were seen in 39.3% of patients and major complications were in 4.4%. The most common major complications were epistaxis and worsened vision. Most minor complications involved electrolyte/sodium dysregulation. At 3-6 months, local control on imaging was achieved in 94.8% of cases and residual/recurrent tumor was seen in 19.3%. Reoperations were required for 2.9% of cases. On multivariate analysis, previous surgery was significantly predictive of intraoperative complications (6.14 OR, p < 0.01) and major complications (14.12 OR, p < 0.01). Previous pharmacotherapy (0.27 OR, p = 0.02) and cavernous sinus invasion (0.19 OR, p = 0.03) were significantly protective against early endocrinological cure. Knosp classification was highly predictive of residual tumor or PST recurrence on 6-month follow-up imaging (4.60 OR, p < 0.01). There was noted institutional variation in clinical factors and outcomes.

CONCLUSION

Our results evaluate a modern, multicenter, global series of PST. These data can serve as a benchmark to compare with DA therapy and other surgical series. Further study and longer term outcomes could provide insight into how patients benefit from surgical treatment.

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

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

Care trajectories of surgically treated patients with a prolactinoma: why did they opt for surgery?

PURPOSE

To describe care trajectories in patients with prolactinoma, aiming to clarify the rationale for surgery.

METHODS

Retrospective observational cohort study of consecutive patients with prolactinoma undergoing surgery from 2017 to 2019 at the referral center (RC), prior to surgery being considered a viable treatment option (i.e. PRolaCT study). Demographics and clinical data (type and duration of pretreatment and surgical indications, goals, and outcomes) were collected from patient records. Care trajectories were divided into three phases: (1) diagnosis and initial treatment, (2) endocrine treatment at the RC, and (3) surgical treatment.

RESULTS

40 patients were included (31 females (77.5%), median age 26.5 (14-63) years. Indications for surgery were dopamine agonist (DA) intolerance (n = 31, 77.5%), resistance (n = 6, 15.0%), and patient/physician preference (n = 3, 7.5%). Patients were pretreated with DA (n = 39 (97.5%)), and surgery (n = 3 (7.5%)). Median disease duration at surgery was 4 (0-27) years. Primary surgical goal was total resection in 38 patients (95.0%), of which biochemical remission was achieved 6 months postoperatively in 23 patients (62.2%), and clinical remission in 6 patients (16.2%), missing data n = 1.

CONCLUSION

Care trajectories were highly individualized based on patient and tumor characteristics, as well as the multidisciplinary team's assessment (need for alternative treatment, surgical chances and risks). Most patients were pretreated pharmacologically and had broad variation in timing of referral, undergoing surgery as last-resort treatment predominantly due to DA intolerance. High quality imaging and multidisciplinary consultations with experienced neurosurgeons and endocrinologists enabling treatment tailored to patients' needs were prerequisites for adequate counseling in treatment of patients with prolactinoma.

Prevalence and clinical correlations of SF3B1 variants in lactotroph tumours

OBJECTIVE

A somatic mutational hotspot in the SF3B1 gene was reported in lactotroph tumours. The aim of our study was to examine the prevalence of driver SF3B1 variants in a multicentre independent cohort of patients with lactotroph tumours and correlate with clinical data.

DESIGN AND METHODS

This was a retrospective, multicentre study involving 282 patients with lactotroph tumours (including 6 metastatic lactotroph tumours) from 8 European centres. We screened SF3B1 exon 14 hotspot for somatic variants using Sanger sequencing and correlated with clinicopathological data.

RESULTS

We detected SF3B1 variants in seven patients with lactotroph tumours: c.1874G > A (p.Arg625His) (n = 4, 3 of which metastatic) and a previously undescribed in pituitary tumours variant c.1873C > T (p.Arg625Cys) (n = 3 aggressive pituitary tumours). In two metastatic lactotroph tumours with tissue available, the variant was detected in both primary tumour and metastasis. The overall prevalence of likely pathogenic SF3B1 variants in lactotroph tumours was 2.5%, but when we considered only metastatic cases, it reached the 50%. SF3B1 variants correlated with significantly larger tumour size; higher Ki67 proliferation index; multiple treatments, including radiotherapy and chemotherapy; increased disease-specific death; and shorter postoperative survival.

CONCLUSIONS

SF3B1 variants are uncommon in lactotroph tumours but may be frequent in metastatic lactotroph tumours. When present, they associate with aggressive tumour behaviour and worse clinical outcome.

Surgery as first-line treatment for prolactinoma? Discussion of the literature and results of a consecutive series of surgically treated patients

Initial treatment for prolactinoma is usually conservative with dopamine agonists. However, the duration of treatment is often lifelong and can be associated with significant side effects. Surgical outcomes are usually favorable and treatment complications low, raising the question whether surgical therapy should be included earlier in the treatment of prolactinoma. The aim of this study was to analyze the outcome of surgical resection of prolactinomas at our institution, to compare it with other published surgical and conservative series and to discuss the role of surgery in modern prolactinoma therapy. The authors reviewed a database of single-center consecutively operated prolactinoma cases and analyzed the extent of resection (EOR), endocrinological and neurological outcomes, and complications. Thirty patients were analyzed. Mean patient age was 37.2 ± 15.5 years (range 16-76) and consisted of 17 (56.7%) females and 13 (43.3%) males. Twenty-one patients (70%) failed medical therapy, the main reasons being intolerable side effects in 11 cases (52.4%) and insufficient response in 10 cases (47.6%). Nine patients (30%) received no medical treatment prior to surgery, of which five (55.6%) were operated because of pituitary apoplexy, two (22.2%) because of acute visual deterioration and two (22.2%) refused medical treatment and opted for surgery as first-line treatment. Of the 30 operated tumors, 56.7% (n = 17) were microadenomas, 30% (n = 9) were macroadenomas (≥ 10 mm), and 13.3% (n = 4) were giant adenomas (≥ 40 mm). GTR was achieved in 75% (n = 21) of cases. The overall remission rate was 63.3%. MRI showed a residual tumor in seven patients (25%), typically with invasive growth. Postoperative CSF leaks did not occur. Mean follow-up was 34.9 ± 60.3 months (range 0-246 months). Endocrine remission was defined as a morning fasting basal PRL level of 22.3 < ng/mL and measured at the last available follow-up. Postoperative Prolactine levels were missing in three patients. Our analysis describes a highly selected sample with a disproportionate number of larger, invasive tumors and emergency cases. Nevertheless, the results are satisfactory and comparable with other published series. The consistently good results of transphenoidal surgery, especially for microprolactinomas, have led to a greater acceptance of surgery in the treatment of prolactinomas in recent years. The timing of surgery in each individual case must be determined by a multidisciplinary team to ensure the best possible outcome.

Operative treatment of cystic prolactinomas: a retrospective study

BACKGROUND

The optimal therapeutic approach for cystic prolactinomas remains unclear. This study aimed to evaluate the remission rates of prolactinoma patients after surgical treatment and the risk factors affecting postoperative remission in cystic prolactinoma patients.

METHODS

The clinical data were retrospectively compiled from 141 patients with prolactinomas (including 41 cases of cystic prolactinomas, 21 cases of solid microprolactinomas and 79 cases of solid macroprolactinomas) who underwent transsphenoidal surgery (TSS) between April 2013 and October 2021 at the First Affiliated Hospital of Sun Yat-sen University.

RESULTS

Early postoperative remission was achieved in 65.83% (n = 27/41) of cystic prolactinomas, 80.95% (n = 17/21) of solid microprolactinomas and 40.51% (n = 32/79) of solid macroprolactinomas. The mean length of follow up in all patients was 43.95 ± 2.33 months (range: 6-105 months). The follow-up remission rates were 58.54%, 71.43% and 44.30% in cystic, solid micro- and solid macroprolactinomas, respectively. For cystic prolactinomas, the early postoperative remission rates in the patients with preoperative dopamine agonists (DA) treatment were significantly higher than those without preoperative DA treatment (p = 0.033), but the difference in the follow-up remission rates between these two groups was not significant (p = 0.209). Multivariate stepwise logistic regression analysis indicated that tumor size and preoperative prolactin (PRL) levels < 200 ng/ml were independent predictors for early postoperative remission in cystic prolactinomas.

CONCLUSION

For cystic prolactinomas, tumor size and preoperative PRL levels were independent predictors of early postoperative remission. Preoperative DA therapy combined with TSS may be more beneficial to cystic prolactinoma patients.

Surgical Technique and Efficacy Analysis of Extra-pseudocapsular Transnasal Transsphenoidal Surgery for Pituitary Microprolactinoma

OBJECTIVE

To elucidate the role of transsphenoidal surgery in the treatment of pituitary microprolactinoma.

METHODS

The clinical data of 107 prolactinoma cases treated by extra-pseudocapsular transnasal transsphenoidal surgery (ETTS) for different indications in our department since 2011 was retrospectively analyzed.

RESULTS

The most common indication was the ineffectiveness of oral medication (41.1%), followed by the personal willingness of the patient (35.5%), and 20.6% of the patients were young women with clear tumor boundaries. The pseudocapsule was not observed in 63 cases (58.9%), incomplete pseudocapsule was observed in 26 cases (24.3%), and complete pseudocapsule in 18 cases (16.8%). A total of 97 patients (90.7%) obtained 1-year post-operation remission. According to the relative location of the adenoma and pituitary gland on the MRI scan, 46 patients were classified into a central type, 59 a lateral type, and 2 a supra-pituitary type. Two patients developed hypogonadism, one patient developed hypocortisolism, and one patient developed post-operative hypothyroidism. Two patients were administrated with hormone replacement treatment, and the treatment was stopped within one week. There was no permanent hypopituitarism. Further investigation demonstrated that the adenoma types could affect the remission rates of hyperprolactinemia and gross total resection rate in microprolactinoma.

CONCLUSION

ETTS was an effective treatment for pituitary microprolactinomas. This could be the first choice for patients who presented enclosed adenoma on the MRI and were potentially curable in a preoperative evaluation. Maximal safe removal of the adenoma by ETTS with the aim to increase the sensitivity of the drugs was also recommended for patients with invasive dopamine agonist resistant prolactinomas and patients with difficulty in childbirth.

Extra-pseudocapsular Transnasal Transsphenoidal Resection of Pituitary Macroadenoma: Technique Note and Evaluation of Endocrine Function

OBJECTIVE

In this study, we investigated the surgical technique and endocrine assessment of pituitary function of patients with macroadenoma treated by extra-pseudocapsular transnasal transsphenoidal surgery (ETTS).

METHODS

Clinical data of 144 patients with pituitary macroadenomas in the same surgical group at the Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were retrospectively analyzed from January 2019 to June 2021. Based on the results of the endocrinological evaluation and MRI examinations before and after surgery, the fluctuation of pituitary function and the extent of resection were analyzed. Multiple Logistic regression analysis was used to determine the predictors affecting postoperative tumor residual.

RESULTS

Among the 144 patients with pituitary macroadenomas, 72 (50.0%) were female and 72 (50.0%) were male, the median age was 50 years, 26 (18.1%) had invasiveness grade 0, 46 (31.9%) had grade I, 57 (39.6%) had grade II, and 15 (10.4%) had grade III according to Lu's classification method. Based on observation during surgery, 37 cases (25.7%) had no pseudocapsule, 54 cases (37.5%) had incomplete pseudocapsule, and 53 cases (36.8%) had intact pseudocapsule. In addition, 91 (63.2%) patients had total resection, 39 (27.1%) had subtotal resection, and 14 (9.7%) had partial resection. As for anterior pituitary function, 13 of 19 hypothyroid patients had recovery after surgery, with a remission rate of 68.4%. Eighteen of the 26 decreased cortisol patients got back to normal, with a remission rate of 69.2%. A total of 27 of 51 patients with hypogonadism improved, with a remission rate of 52.9%. Univariate and multivariate analyses indicated that gender, tumor size, and invasiveness were predictors of postoperative residual in patients (P<0.05).

CONCLUSION

The results showed that ETTS is an effective treatment modality for restoring the function of pituitary gland of the patients with macroadenomas. Tumor size and invasiveness are predictors of the extent of surgical resection and postoperative residual of macroadenomas.

The value of intraoperative MRI for resection of functional pituitary adenomas-a critical assessment of a consecutive single-center series of 114 cases

This series sought to evaluate the role of intraoperative MRI (iMRI) for resection of functional pituitary adenomas (FPAs). We retrospectively reviewed clinical data of 114 consecutive FPAs with excessive hormone secretion treated with transsphenoidal surgery and iMRI during 01/2010-12/2017. We focused on iMRI findings, extend of resection and postoperative hormonal remission. Variables of incomplete resections and persistent hormone excess were evaluated by binary regression. Patients with FPAs presented with hypercortisolism (n = 23, 20%), acromegaly (n = 56, 49%), and as prolactinomas (n = 35, 31%) resistant to medical treatment. Preoperative MRI showed 81 macroadenomas (71%) and optic system involvement in 41 cases (36%). IMRI was suggestive for residual tumor in 51 cases (45%). Re-inspection of the cavity cleared equivocal findings in 16 cases (14%). Additional tumor was removed in 22 cases (19%). Complete resection was achieved in 95 cases (83%). Postoperative morbidity was low (1.7% revision surgeries, 0.8% permanent diabetes insipidus). Overall hormonal remission-rate was 59% (hypercortisolism 78%, acromegaly 52%, prolactinoma 57%). Supra- and parasellar invasion and preoperative visual impairment were significant predictors for incomplete resections despite use of iMRI. Risk for persistent hormone excess was increased sevenfold after incomplete resections. IMRI enabled reliable identification of tumor remnants during surgery and triggered further resection in a considerable proportion of cases. Nevertheless, tumor size and invasiveness set persistent boundaries to the completeness of resections. The low rate of surgical complications could point at a less invasive iMRI-guided surgical approach while achieving a complete tumor resection was a crucial determinant for hormonal outcome.

β-Catenin is reduced in membranes of human prolactinoma cells and it is inhibited by temozolomide in prolactin secreting tumor models

INTRODUCTION: Prolactinomas are the most frequent pituitary tumor subtype. Despite most of them respond to medical treatment, a proportion are resistant and become a challenge in clinical management. Wnt/β-Catenin pathway has been implicated in several cancers including pituitary tumors and other sellar region malignancies. Interestingly, Wnt/β-Catenin inhibition augments the cytotoxicity of the chemotherapeutic agent Temozolomide (TMZ) in different cancers. TMZ is now being implemented as rescue therapy for aggressive pituitary adenoma treatment. However, the molecular mechanisms associated with TMZ action in pituitary tumors remain unclear. OBJECTIVES: Our aims in the present study were to evaluate differential β-Catenin expression in human resistant prolactinomas and Wnt/β-Catenin signaling activation and involvement in Prolactin (PRL) secreting experimental models treated with TMZ. RESULTS: We first evaluated by immunohistochemistry β-Catenin localization in human resistant prolactinomas in which we demonstrated reduced membrane β-Catenin in prolactinoma cells compared to normal pituitaries, independently of the Ki-67 proliferation indexes. In turn, in vivo 15 mg/kg of orally administered TMZ markedly reduced PRL production and increased prolactinoma cell apoptosis in mice bearing xenografted prolactinomas. Intratumoral β-Catenin strongly correlated with Prl and Cyclin D1, and importantly, TMZ downregulated both β-Catenin and Cyclin D1, supporting their significance in prolactinoma growth and as candidates of therapeutic targets. When tested in vitro, TMZ directly reduced MMQ cell viability, increased apoptosis and produced G2/M cell cycle arrest. Remarkably, β-Catenin activation and VEGF secretion were inhibited by TMZ in vitro. CONCLUSIONS: We concluded that dopamine resistant prolactinomas undergo a β-Catenin relocalization in relation to normal pituitaries and that TMZ restrains experimental prolactinoma tumorigenicity by reducing PRL production and β-Catenin activation. Together, our findings contribute to the understanding of Wnt/β-Catenin implication in prolactinoma maintenance and TMZ therapy, opening the opportunity of new treatment strategies for aggressive and resistant pituitary tumors.

Surgical Treatment of Cystic Pituitary Prolactin-Secreting Macroadenomas: A Single Center Study of 42 Patients

This study evaluated the therapeutic effects of surgical treatment of cystic pituitary prolactin-secreting macroadenomas. The clinical data of 42 patients with cystic pituitary prolactin-secreting macroadenomas were retrospectively analyzed. Patients were divided into medication plus surgery and surgery alone groups based on the regularity of bromocriptine treatment before surgery. Both groups underwent extra-pseudocapsular transsphenoidal surgery for tumor resection, and postoperative images and clinical follow-up were retrospectively reviewed. We also evaluated patients who opted for long-term treatment with bromocriptine. In the medication plus surgery group, the long-term surgical cure rate and comprehensive remission rate were 33.3% and 41.7%, while in the surgery alone group they were 69.2% and 80.8%, respectively. No severe or permanent complications occurred, and the surgical complication morbidity rate was 10.5%. The rate of tumor progression during the long-term follow-up was 33.3% and 7.7% in the medication plus surgery and surgery alone groups, respectively. The time required for prolactin levels to return to normal in the surgery alone group was significantly faster and the proportion that returned to normal was significantly higher. Direct surgical treatment after diagnosis combined with postoperative individualized bromocriptine adjuvant therapy had better efficacy in patients with cystic pituitary prolactin-secreting macroadenomas, but its long-term effectiveness requires further follow-up.

Management of prolactinomas in children and adolescents; which factors define the response to treatment?

PURPOSE

Prevalence, presentation and clinical outcome of prolactinomas vary in children and adults. In this study, we evaluated the clinical features and outcome of children and adolescents with prolactinoma to identify the differences from that of adults, and thus to establish the management strategies for this age group.

METHODS

Patients with prolactinoma diagnosed before 18 years of age from a single center in the last 20-years were included. Clinical and laboratory data, radiological findings and treatment outcome were evaluated retrospectively.

RESULTS

Twenty-eight patients (23 female; 82.1%) with prolactinoma were included. Median age at diagnosis was 15.2 years (12.6-17.7 years) in girls, 12.9 years (12.0-16.7 years) in boys. First line treatment was cabergoline in 82% of patients and normal prolactin level was achieved with maximum dose of 2 mg/week in 78%. Surgery was required in 28% of patients. Adenomas < 13.5 mm responded conventional doses of CAB. Adenomas > 30 mm were drug resistant or required surgery. Adenomas between 13.5 mm and 30 mm with invasion/extension were more likely to have drug resistance. CAB had to be continued following surgery in all patients. One macroprolactinoma had an increase in size which was accompanied with increasing prolactin level.

CONCLUSIONS

All microprolactinomas responded well to DA treatment. However, all adenomas larger than 30 mm was resistant to CAB or required surgery. Probability of drug resistance and requirement of second line therapy were higher in adenomas between 13.5 mm and 30 mm with invasion/extension. Doses over 2 mg/week of CAB in drug-resistant patients may not provide additional benefit. The frequency of follow-up MRI could be determined based on prolactin levels and emergence of new neurological symptoms.

EGFR/ErbB2-Targeting Lapatinib Therapy for Aggressive Prolactinomas

CONTEXT

Approximately 10% to 20% of prolactinomas are resistant to dopamine agonist therapy. The ErbB signaling pathway may drive aggressive prolactinoma behavior.

OBJECTIVE

We evaluated lapatinib, an ErbB1-epidermal growth factor receptor (EGFR)/ErbB2 or human EGFR2 (HER2) tyrosine kinase inhibitor (TKI), in aggressive prolactinomas.

DESIGN

A prospective, phase 2a multicenter trial was conducted.

SETTING

This study took place at a tertiary referral pituitary center.

PATIENTS

Study participants included adults with aggressive prolactinomas showing continued tumor growth despite maximally tolerated dopamine agonist therapy.

INTERVENTION

Intervention included oral lapatinib 1250 mg/day for 6 months.

MAIN OUTCOME MEASURES

The primary end point was 40% reduction in any tumor dimension assessed by magnetic resonance imaging at study end; tumor response was assessed by Response Evaluation Criteria in Solid Tumors criteria. Secondary end points included prolactin (PRL) reduction, correlation of response with EGFR/HER2 expression, and safety.

RESULTS

Owing to rigorous inclusion criteria, of 24 planned participants, only 7 consented and 4 were treated. None achieved the primary end point but 3 showed stable disease, including 2 with a 6% increase and 1 with a 16.8% decrease in tumor diameter. PRL response was not always concordant with tumor response, as 2 showed 28% and 59% increases in PRL. The fourth participant had a PRL-secreting carcinoma and withdrew after 3 months of lapatinib because of imaging and PRL progression. EGFR/HER2 expression did not correlate with treatment response. Lapatinib was well tolerated overall, with reversible grade 1 transaminitis in 2 patients, grade 2 rash in 2 patients, and grade 1 asymptomatic bradycardia in 2 patients.

CONCLUSIONS

An oral TKI such as lapatinib may be an effective option for a difficult-to-treat patient with an aggressive prolactinoma.

The optimal numerosity of the referral population of pituitary tumors centers of excellence (PTCOE): A surgical perspective

Surgical experience is of paramount importance to reach therapeutic success and minimize operative complications. In the field of pituitary surgery, this led to the concept of Pituitary Center of Excellence (PTCOE) defined as a center where an interdisciplinary team works in collaboration and where surgeons can be trained appropriately to reach and keep excellence in daily practice. To review the literature to define the optimal referral population size to establish a PTCOE to optimize both training and specific field research. A review of the literature was performed about epidemiology. The time needed to observe 200 cases of PAs in a single PTCOE and to reach the minimal surgical experience threshold (MSET) was calculated for different referral population groups. The time needed to reach MSET decreased as population size increased. We defined a population as the optimal one to be served by a single PTCOE with a single dedicated neurosurgeon. PTCOEs should be established after an analysis of the referral population, number of cases suitable for surgical treatment and number of dedicated neurosurgeons.

Endoscopic Surgery for Pituitary Tumors

Endoscopic transsphenoidal surgery for pituitary adenoma is a safe and highly effective first-line treatment that is well tolerated by patients. Potential complications are plenty, and there is a large variation in complexity of surgery. This article presents the philosophy, surgical techniques, and outcomes of a high-volume pituitary adenoma center. Three surgical videos illustrate some procedures. The experience has reinforced the authors' belief that experience and surgical volume are key to high quality of care.

Prolactinomas in males: any differences?

CONTEXT

Prolactinomas in men are usually large and invasive, presenting with signs and symptoms of hypogonadism and mass effects, including visual damage. Prolactin levels are high, associated with low testosterone, anemia, metabolic syndrome and if long-standing also osteoporosis.

RESULTS

Medical treatment with the dopamine agonist, cabergoline, became the preferred first-line treatment for male prolactinomas as well as for giant tumors, leading to prolactin normalization in ~ 80% of treated men, and tumor shrinkage, improved visual fields and recovery of hypogonadism in most patients. Multi-modal approach including surgery and occasionally radiotherapy together with a high-dose cabergoline is saved for resistant and invasive adenomas. Experimental treatments including temozolomide or pasireotide may improve clinical response in men harboring resistant prolactinomas.

CONCLUSIONS

Compared to other pituitary adenomas, secreting and non-secreting, where pituitary surgery is the recommended first-line treatment, men with prolactinomas will usually respond to medical treatment with no need for any additional treatment.

Prolactinomas: Prognostic Factors of Early Remission After Transsphenoidal Surgery

Background and Objective: Most patients with prolactinomas receive pharmacological treatment only, resulting in limited research on the predictors of successful prolactinoma surgery. In this study, we analyzed whether early postoperative serum prolactin concentrations and selected tumor characteristics could predict early, hormonal remission after removal of prolactinomas. Methods: We prospectively enrolled 48 consecutive patients with prolactinomas who underwent transsphenoidal resection performed by the same surgeon. Early remission, defined as a lack of hyperprolactinemia symptoms and normalization of serum prolactin concentration, was ascertained in all patients at 3 months. We evaluated the invasiveness of prolactinomas on the Knosp grading scale and measured serum prolactin concentrations on the first postoperative day. Routine immunohistochemical analysis, evaluation for plurihormonality, and assessment of the Ki-67 proliferation index (<3 or ≥3% of positive nuclei) were performed in all tumor samples. Results: Of 48 patients, 38 (79%) achieved early biochemical remission at 3 months. Patients in early remission at 3 months had lower serum prolactin concentrations on the first postoperative day than patients with recurrent or persistent hyperprolactinemia (p < 0.001). Using univariate logistic regression, larger maximum tumor diameter (p = 0.014), higher Knosp grade (p < 0.001), and plurihormonality predicted remission at 3 months (p = 0.021). However, using multivariate stepwise logistic regression, only the Knosp grade remained significant (p < 0.001). Conclusions: Radiological assessment of prolactinoma invasiveness (Knosp grades) and early postoperative serum prolactin concentrations are important predictors of early remission following transsphenoidal prolactinoma resection.

The epidemiology, diagnosis and treatment of Prolactinomas: The old and the new

Prevalence and incidence of prolactinomas are approximately 50 per 100,000 and 3-5 new cases/100,000/year. The pathophysiological mechanism of hyperprolactinemia-induced gonadotropic failure involves kisspeptin neurons. Prolactinomas in males are larger, more invasive and less sensitive to dopamine agonists (DAs). Macroprolactin, responsible for pseudohyperprolactinemia is a frequent pitfall of prolactin assay. DAs still represent the primary therapy for most prolactinomas, but neurosurgery has regained interest, due to progress in surgical techniques and a high success rate in microprolactinoma, as well as to some underestimated side effects of long-term DA treatment, such as impulse control disorders or impaired quality of life. Recent data show that the suspected effects of DAs on cardiac valves in patients with prolactinomas are reassuring. Finally, temozolomide has emerged as a valuable treatment for rare cases of aggressive and malignant prolactinomas that do not respond to all other conventional treatments.