Medical Versus Surgical Management of Prolactinomas

Long-term IGF-1 monitoring in prolactinoma patients treated with cabergoline might not be indicated

PURPOSE

Cabergoline (CAB) therapy for prolactinomas has been associated with serum IGF-1 levels modifications, with recent reports indicating a paradoxical increase of IGF-1 levels during ongoing therapy. As a result, IGF-1 measurement has been proposed not only at diagnosis of a prolactinoma, but also during follow-up. In this follow-up study on prolactinoma patients with chronic CAB therapy, we investigated whether there are long-term changes in IGF-1 levels that necessitate continuous monitoring.

METHODS

We reviewed our institutional database on prolactinoma patients with long-term CAB therapy, in whom IGF-1 levels were measured at baseline, at 3-months follow-up and in the long term.

RESULTS

Chronic CAB therapy was noted in 20 patients (13 men, 7 women). Median (±SD) age was 43.5 ± 12.6 years. 17 (85%) patients presented with a macroprolactinoma. Median CAB treatment time was 75 ± 43 months (range 24-187). Median IGF-1 levels increased at last follow-up, though not significantly; from 122 ± 37 ng/ml (IQR 104-160 ng/ml) to 133 ± 54 (IQR 121-162 ng/ml), p = 0.10. Thereby, 18 (90%) patients showed normal serum IGF-1 levels adjusted for age, one (5%) patient above (1.05 × ULN) and 1 (5%) patient below the normal range (0.34 × ULN). No patient was or became symptomatic of acromegaly.

CONCLUSION

Our long-term results indicate that chronic treatment with CAB in prolactinoma patients does not significantly modify serum IGF-1 levels. Bearing in mind the sample size of this study, continuing IGF-1 monitoring is not indicated in prolactinoma patients with long-term CAB therapy.

Endoscopic Transsphenoidal Surgery of Microprolactinomas: A Reappraisal of Cure Rate Based on Radiological Criteria

BACKGROUND

Current standard treatment of microprolactinomas is dopamine agonist therapy. As this drug treatment is lifelong in up to 80% of cases, many patients consult pituitary surgeons regarding a surgical alternative.

OBJECTIVE

To identify prognostic criteria for surgical remission, we reviewed outcomes of our series of microprolactinomas treated with endoscopic transsphenoidal surgery, with a special emphasis on magnetic resonance adenoma delineation and position.

METHODS

Our study cohort comprises a single center series of 60 patients operated for histopathologically verified magnetic resonance imaging unequivocally identifiable endosellar microprolactinoma between 2003 and 2017. In 31 patients the adenoma was enclosed by pituitary gland (group ENC), in 29 patients the adenoma was located lateral to the gland adherent to the medial cavernous sinus wall (group LAT).

RESULTS

After a mean follow-up of 37 mo (range 4-143 mo), remission rate was significantly higher in adenomas enclosed by pituitary gland (group ENC) than adenomas located lateral to the gland (group LAT), with 87% vs 45%, P = .01. Intraoperatively, 4 patients showed signs of invasiveness. Preoperative prolactin levels did not differ between the groups (mean 155 and 187 ng/ml in group ENC and LAT, respectively).A binary logistic regression model revealed that only the radiological criteria applied showed a significant correlation (P = .003) with endocrine remission.

CONCLUSION

According to our results, remission rate is significantly higher in microprolactinomas enclosed by the pituitary gland. However, the decision for surgery should take into account surgeons experience and possibility of complications.

Medical versus surgical treatment of prolactinomas: an analysis of treatment outcomes

INTRODUCTION

Prolactinomas are unique tumors that may go into both hormonal and radiographic remission with dopamine agonist therapy or transsphenoidal surgery. Regardless of modality, the goals of therapy remain the same: (1) biochemical remission, including reduction of prolactin and normalization of sex hormones; (2) radiographic tumor control, with a range including prevention of tumor growth, tumor regression, or complete tumor resolution; (3) resolution of preoperative symptoms, including those that are hormonal or neurologic; and (4) prevention of new hypopituitarism or new neurologic symptoms.

AREAS COVERED

In the following review, we performed a search of the literature using keywords 'prolactinoma,' 'dopamine agonist,' 'surgery,' 'cost-effectiveness,' 'recurrence,' and 'complication' to compare the relative merits of medical versus surgical therapy for prolactinoma, including special circumstances such as cystic tumors, pregnant patients, and the cost-effectiveness of different strategies.

EXPERT COMMENTARY

Medical therapy can offer a cure, but surgery provides an important adjunct to patients with resistance or intolerance to dopamine agonists, and offers excellent outcomes including when combined with continued postoperative medical therapy. Further head to head comparisons will benefit patients and practitioners weighing the relative risks and benefits of medical and surgical intervention, including the issue of their relative cost-effectiveness.

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

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

Reoperative endoscopic endonasal surgery for residual or recurrent pituitary adenomas

OBJECTIVE

Regrowth of the lesion after surgical removal of pituitary adenomas is uncommon unless subtotal resection was originally achieved in the first surgery. Treatment for recurrent tumor can involve surgery or radiotherapy. Locations of residual tumor may vary based on the original approach. The authors evaluated the specific sites of residual or recurrent tumor after different transsphenoidal approaches and describe the surgical outcome of endoscopic endonasal transsphenoidal reoperation.

METHODS

The authors analyzed a prospectively collected database of a consecutive series of patients who had undergone endoscopic endonasal surgeries for residual or recurrent pituitary adenomas after an original transsphenoidal microscopic or endoscopic surgery. The site of the recurrent tumor and outcome after reoperation were noted and correlated with the primary surgical approach. The chi-square or Fisher exact test was used to compare categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between surgical groups.

RESULTS

Forty-one patients underwent surgery for residual/recurrent pituitary adenoma from 2004 to 2015 at Weill Cornell Medical College. The previous treatment was a transsphenoidal microscopic (n = 22) and endoscopic endonasal (n = 19) surgery. In 83.3% patients (n = 30/36) there was postoperative residual tumor after the initial surgery. A residual tumor following endonasal endoscopic surgery was less common in the sphenoid sinus (10.5%; 2/19) than it was after microscopic transsphenoidal surgery (72.7%; n =16/22; p = 0.004). Gross-total resection (GTR) was achieved in 58.5%, and either GTR or near-total resection was achieved in 92.7%. Across all cases, the average extent of resection was 93.7%. The rate of GTR was lower in patients with Knosp-Steiner Grade 3–4 invasion (p < 0.0005). Postoperative CSF leak was seen in only one case (2.4%), which stopped with lumbar drainage. Visual fields improved in 52.9% (n = 9/17) of patients and were stable in 47% (n = 8/17). Endocrine remission was achieved in 77.8% (n = 14/18) of cases, 12 by surgery alone and 2 by adjuvant medical (n = 1) and radiation (n = 1) therapy. New diabetes insipidus occurred in 4.9% (n = 2/41) of patients—in one of whom an additional single anterior hormonal axis was compromised—and 9.7% (n = 4/41) of patients had a new anterior pituitary hormonal insufficiency.

CONCLUSIONS

Endonasal endoscopic reoperation is extremely effective at removing recurrent or residual pituitary adenomas that remain after a prior surgery, and it may be preferable to radiation therapy particularly in symptomatic patients. Achievement of GTR is less common when lateral cavernous sinus invasion is present. The locations of residual/recurrent tumor were more likely sphenoidal and parasellar following a prior microscopic transsphenoidal surgery and sellar following a prior endonasal endoscopic surgery.

Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas

Background Few studies address the cost of treating prolactinomas. We performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings.

[Indications for surgical treatment of prolactin-secreting pituitary adenomas]

Prolactinomas account for about 40% of all pituitary adenomas. The main treatment for prolactinomas is undoubtedly therapy with dopamine agonists (DAs). However, prolonged conservative treatment (for many years or even throughout life) that is necessary for permanent control of the disease makes some patients refuse pharmacological treatment for various reasons. In addition, not all prolactinomas respond to DAs therapy. Sometimes, the patient is not able to continue treatment because of the severity of side effects. Along with tumor resistance to therapy and patient intolerance of DAs, complications (liquorrhea, hemorrhage in the tumor) may occur during conservative treatment. In these cases, surgery is necessary. The paper analyzes the modern literature on various treatment options for prolactin-secreting pituitary adenomas and defines the indications for surgical treatment.

Effect of the preoperative use of dopamine agonists in the postoperative course of prolactinomas: a systematic review

OBJECTIVE

Since the 1980s, it has been discussed whether the preoperative treatment of prolactinomas with dopamine agonists (DAs) is beneficial or detrimental regarding postoperative residue or recurrence. Many neurosurgeons have emphasized the difficulties caused by fibrosis during the ablation of such prolactinomas.

METHODS

From February to December 2012, the authors searched electronic databases and book chapters published from 1991 to 2012; a total of 3,771 articles and 37 book chapters were searched. Ten articles that explicitly addressed this issue were identified.

RESULTS

Five articles reported that preoperative treatment did not affect postoperative status. One article described a positive influence of preoperative treatment with DAs (P < .01), and 3 articles found a negative influence (P = .040, P = .02, no significance value reported). One article described histopathological evidence of tumor fibrosis that was found intraoperatively after preoperative DA treatment.

CONCLUSIONS

This systematic review did not identify any strong evidence that preoperative treatment of prolactinomas with DAs is harmful or beneficial. Therefore, further studies are needed.

Update on prolactinomas. Part 1: Clinical manifestations and diagnostic challenges

The authors provide an update on the clinical manifestations and diagnostic challenges of prolactinomas. Prolactinomas are the most common pituitary adenoma seen in clinical practice. Secondary causes of hyperprolactinemia should be ruled out by assessment of the clinical history, including current medications, physical examination, pregnancy test, routine biochemical analysis with a thyroid function test, and neuroimaging, before a confirmatory diagnosis of prolactinoma is made. Prolactinomas are associated with endocrine dysfunction, affecting gonadal function and causing neurological deficits due to mass effect. The progress in elucidating the pathogenesis of prolactinomas and advances in diagnostic methods, including more sensitive diagnostic hormone assays and neuroimaging, have enriched the current diagnostic approach and management. Making the correct diagnosis is crucial to implementing the appropriate therapy. Dopamine agonist therapy remains the first line of treatment for prolactinomas, as it is effective in normalizing serum prolactin levels and reducing tumor size. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or for those experiencing progressive neurological deficits. Nevertheless, curative surgical resection as a primary mode of treatment for smaller prolactinomas has recently gained attention as an alternative to lifelong dopamine agonist treatment.

The effect of metformin on prolactin levels in patients with drug-induced hyperprolactinemia

BACKGROUND

In bromocriptine-treated hyperprolactinemic patients with impaired glucose tolerance, metformin was found to reduce plasma levels of prolactin. No previous study has investigated its impact on plasma prolactin in patients with drug-induced hyperprolactinemia.

METHODS

The study included 20 women with antipsychotic-induced hyperprolactinemia and 12 normoprolactinemic women, who, because of coexisting glucose metabolism abnormalities, were treated for 6months with metformin. Hyperprolactinemic patients with prediabetes received moderate doses of metformin (1.7g daily), while hyperprolactinemic and normoprolactinemic patients with type 2 diabetes were treated with high-dose metformin (2.55-3g daily). Fasting plasma glucose levels, the homeostatic model assessment 1 of insulin resistance ratio (HOMA1-IR), glycated hemoglobin, as well as plasma levels of prolactin, thyrotropin, adrenocorticotropic hormone and insulin-like growth factor-1 were assessed at baseline and after 6months of treatment.

RESULTS

Despite reducing plasma glucose, HOMA1-IR, and glycated hemoglobin in all treatment groups, metformin decreased prolactin levels only if given at high doses to patients with elevated prolactin levels. No changes in thyrotropin, adrenocorticotropic hormone, and insulin-like growth factor-1 were observed in any treatment groups.

CONCLUSIONS

The obtained results suggest that the effect of metformin on plasma prolactin depends on its dose and is observed only in patients with elevated levels of this hormone.

Gamma Knife radiosurgery for medically and surgically refractory prolactinomas: long-term results

INTRODUCTION

Prolactinomas are the most common functioning pituitary adenomas. Dopamine agonists (DA) are generally very effective in treating prolactinomas by inducing tumor volume regression and endocrine remission. A minority of patients do not respond to DA or are intolerant because of side-effects. Microsurgical resection when possible is the next treatment option, but cavernous sinus, dural, or bone involvement may not allow for complete resection.

OBJECTIVE

We reviewed the outcome of patients with medically and surgically refractory prolactinomas treated with Gamma Knife radiosurgery (GKRS) during a 22 years follow-up period.

METHODS

We reviewed the patient database at the University of Virginia Gamma Knife center during a 25-year period (1989-2014), identifying 38 patients having neurosurgical, radiological and endocrine follow-up.

RESULTS

Median age at GKRS treatment was 43 years. Median follow-up was 42.3 months (range 6-207.9). 55.3 % (n = 21) were taking a dopamine agonist at time of GKRS. 63.2 % (n = 24) had cavernous sinus tumor invasion. Endocrine remission (normal serum prolactin off of a dopamine agonist) was achieved in 50 % (n = 19). GKRS induced hypopituitarism occurred in 30.3 % (n = 10). Cavernous sinus involvement was shown to be a significant negative prognosticator of endocrine remission. Taking a dopamine agonist drug at the time of GKRS showed a tendency to decrease the probability for endocrine remission.

CONCLUSION

GKRS for refractory prolactinomas can lead to endocrine remission in many patients. Hypopituitarism is the most common side effect of GKRS.

Update on prolactinomas. Part 2: Treatment and management strategies

The authors present an update on the various treatment modalities and discuss management strategies for prolactinomas. Prolactinomas are the most common type of functional pituitary tumor. Effective hyperprolactinemia treatment is of great importance, due to its potential deleterious effects including infertility, gonadal dysfunction and osteoporosis. Dopamine agonist therapy is the first line of treatment for prolactinomas because of its effectiveness in normalizing serum prolactin levels and shrinking tumor size. Though withdrawal of dopamine agonist treatment is safe and may be implemented following certain recommendations, recurrence of disease after cessation of the drug occurs in a substantial proportion of patients. Concerns regarding the safety of dopamine agonists have been raised, but its safety profile remains high, allowing its use during pregnancy. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or are experiencing progressive tumor growth. Surgical resection can also be considered as a primary treatment for those with smaller focal tumors where a biochemical cure can be expected as an alternative to lifelong dopamine agonist treatment. Stereotactic radiosurgery also serves as an option for those refractory to medical and surgical therapy.

Early prediction of long-term response to cabergoline in patients with macroprolactinomas

BACKGROUND

Cabergoline is typically effective for treating prolactinomas; however, some patients display cabergoline resistance, and the early characteristics of these patients remain unclear. We analyzed early indicators predicting long-term response to cabergoline.

METHODS

We retrospectively reviewed the cases of 44 patients with macroprolactinomas who received cabergoline as first-line treatment; the patients were followed for a median of 16 months. The influence of various clinical parameters on outcomes was evaluated.

RESULTS

Forty patients (90.9%) were treated medically and displayed tumor volume reduction (TVR) of 74.7%, a prolactin normalization (NP) rate of 81.8%, and a complete response (CR; TVR >50% with NP, without surgery) rate of 70.5%. Most patients (93.1%) with TVR ≥25% and NP at 3 months eventually achieved CR, whereas only 50% of patients with TVR ≥25% without NP and no patients with TVR <25% achieved CR. TVR at 3 months was strongly correlated with final TVR (R=0.785). Patients with large macroadenomas exhibited a low NP rate at 3 months, but eventually achieved TVR and NP rates similar to those of patients with smaller tumors. Surgery independently reduced the final dose of cabergoline (β=-1.181 mg/week), and two of four patients who underwent surgery were able to discontinue cabergoline.

CONCLUSION

Determining cabergoline response using TVR and NP 3 months after treatment is useful for predicting later outcomes. However, further cabergoline administration should be considered for patients with TVR >25% at 3 months without NP, particularly those with huge prolactinomas, because a delayed response may be achieved. As surgery can reduce the cabergoline dose necessary for successful disease control, it should be considered for cabergoline-resistant patients.

Tumors of the anterior skull base

A variety of histologic tumor types are present in the anterior skull base. Primary tumors of this area may be derived from the bone, paranasal sinuses, nasopharynx, dura, cranial nerves, pituitary gland and brain. Symptoms are caused mostly through mass effect but, if the tumor becomes aggressive, also through invasion. Selection of surgical approaches to the anterior skull base is based upon balancing risk reduction with maximizing extent of resection. Here we review a spectrum of neoplastic entities found in the anterior skull base in adults and discuss clinical and radiographic presentation, treatment options, and outcomes. Surgical resection remains the mainstay in treatment of these tumors, particularly in the hands of experienced surgeons exercising proper patient and case selection.