How to manage intolerance to dopamine agonist in patients with prolactinoma

A Narrative Review of Surgery for Prolactinomas: Considerations and Controversies

For several decades, dopamine agonist therapy has been the mainstay of treatment for prolactinomas, with surgery generally considered a second line for cases failing medical therapy due to intolerance or resistance. There is increasing recognition of the burden of long-term DA therapy; many patients experience debilitating side effects, and emerging evidence demonstrates that the prevalence of impulse control disorders has been vastly underreported. Long-term DA therapy is associated with significant costs to patients and healthcare systems, which is projected to exceed that of surgery in many circumstances. Recent advancements in surgical approaches, including endoscopic transsphenoidal surgery, have led to improved surgical outcomes (82-100% remission rates; serious complication rates < 2%), prompting a reappraisal of the role of surgery for prolactinoma. Favourable surgical outcomes have been observed in both remission and complication rates for microprolactinomas and well-circumscribed macroprolactinomas, leading to consideration of surgery as an earlier, or first-line, option in the treatment paradigm. Potential advantages of surgical management should be weighed against institutional case volume and expertise, the risk of perioperative complications, and the need for adjuvant medical therapy post-operatively. Ultimately, patients and care-providers should engage in shared decision-making following informed discussion about the risks and benefits of both medical and surgical approaches.

Noninvasive Radiomics Approach Predicts Dopamine Agonists Treatment Response in Patients with Prolactinoma: A Multicenter Study

RATIONALE AND OBJECTIVES

The first-line treatment for prolactinoma is drug therapy with dopamine agonists (DAs). However, some patients with resistance to DA treatment should prioritize surgical treatment. Therefore, it is crucial to accurately identify the drug treatment response of prolactinoma before treatment. The present study was performed to determine the DA treatment response of prolactinoma using a clinical radiomic model that incorporated radiomic and clinical features before treatment.

MATERIALS AND METHODS

In total, 255 patients diagnosed with prolactinoma were retrospectively divided to training and validation sets. An elastic net algorithm was used to screen the radiomic features, and a fusion radiomic model was established. A clinical radiomic model was then constructed to integrate the fusion radiomic model and the most important clinical features through multivariate logistic regression analysis for individual prediction. The calibration, discrimination, and clinical applicability of the established models were evaluated. 60 patients with prolactinoma from other centers were used to validate the performance of the constructed model.

RESULTS

The fusion radiomic model was constructed from three significant radiomic features, and the area under the curve in the training set and validation set was 0.930 and 0.910, respectively. The clinical radiomic model was constructed using the radiomic model and three clinical features. The model exhibited good recognition and calibration abilities as evidenced by its area under the curve of 0.96, 0.92, and 0.92 in the training, validation, and external multicenter validation set, respectively. Analysis of the decision curve showed that the fusion radiomic model and clinical radiomic model had good clinical application value for DA treatment response prediction in patients with prolactinoma.

CONCLUSION

Our clinical radiomic model demonstrated high sensitivity and excellent performance in predicting DA treatment response in prolactinoma. This model holds promise for the noninvasive development of individualized diagnosis and treatment strategies for patients with prolactinoma.

A multicenter study of clinical outcomes and volumetric trends in suspected microprolactinomas

The diagnosis of pituitary microprolactinomas is often obscured by relatively low levels of elevated prolactin compared to macroprolactinomas. This may lead to varying patterns of medical therapy versus observation. We sought to correlate prolactin levels in suspected microprolactinomas with tumor volumes and clinical outcomes. This was a multicenter retrospective study of patients with pituitary microadenomas with baseline prolactin levels > 18ng/ml for males and > 30ng/ml for females. A linear-mixed model was used to depict changes in tumor volume over time. There were 65 patients with a mean tumor volume of 95.9mm3 and mean prolactin level of 59.4ng/ml. There were significantly higher prolactin levels in patients with tumors above the mean volume versus below (74.0 versus 53.4ng/ml, p = 0.027). 26 patients were observed, 31 were treated with anti-dopaminergic therapy, and 8 had surgery. There were significantly greater baseline prolactin levels for patients who were treated surgically (mean 86.4ng/ml) than those treated medically (mean 61.7 g/ml) or observed (mean 48.5ng/ml) (p = 0.02). Among the 26 patients who were surveilled, 13 patients demonstrated spontaneous tumor shrinkage, 12 remained stable, and 1 patient's tumor grew but was lost to follow-up. Linear mixed modeling demonstrated a statistically significant rate of tumor shrinkage over time of 3.67mm3/year (p = 0.03). When analyzing patients who were observed versus those requiring surgery after initially being surveilled, there were significantly greater baseline PRL/volume ratios in surgical patients versus those observed (8.1 ng/ml/mm3 versus 2.4 ng/ml/mm3, p = 0.025). Suspected microprolactinomas may demonstrate more convincingly elevated prolactin levels when measuring over 95.9mm3. Tumors with baseline prolactin levels over 50ng/ml may be more inclined to undergo medical treatment. In tumors with levels below 50ng/ml, it may be reasonable to undergo surveillance as these tumors tend to spontaneously shrink over time. In tumors that are surveilled, an elevated baseline PRL/volume ratio of > 8 ng/ml/mm3 may be indicate serial tumor growth that may necessitate medical and/or surgical intervention.

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.

Aromatase inhibitors as a therapeutic strategy for male prolactinoma resistant to dopamine agonists: a retrospective cohort study and literature review

PURPOSE

To assess the effect of letrozole, an aromatase inhibitor (AI), in patients with resistant prolactinoma that presented an increase in serum prolactin (PRL) levels during testosterone replacement therapy (TRT).

METHODS

A retrospective cohort study in a single tertiary care center. From March 2012 to July 2023, 53 male patients over 18 years with prolactinoma were followed in our Neuroendocrine Unit. Of those, 90.6% presented macroadenomas, 41% of them were resistant to cabergoline and 25% presented persistent hypogonadism to whom TRT was indicated. Among them, five presented a significant increase in PRL levels and AI was initiated. All five patients had resistant prolactinomas. One of them was excluded due to tumor aggressiveness and concomitant use of temozolomide during AI therapy.

RESULTS

Four patients were included in the analysis, with a mean age of 28.5 (± 7.5) years, median prolactin of 1060 (600 to 6700) ng/mL and median of the largest tumor diameter of 3.6 (1.5 to 5) cm at the time of prolactinoma diagnosis. On TRT, all presented an increase in serum PRL levels (231 to 396%), with a subsequent decrease (61 to 93%) after adding AI. During AI treatment for a median time of 60.5 (21 to 120) months, tumor shrinkage was observed in two cases (-8 and -3 mm in the maximum diameter) and tumor stability in the other two. No major side effects occurred and AI was well tolerated.

CONCLUSION

AI might be an option for men with resistant prolactinoma who have an increase in PRL levels on TRT. Nevertheless, prospective randomized clinical trials are needed to ensure efficacy and security for this approach.

Ropinirole for the Treatment of Hyperprolactinemia: A Dose-Escalation Study of Efficacy and Tolerability

CONTEXT

Treatment of hyperprolactinemia with ergoline dopamine agonists (DAs) can be complicated by intolerance and resistance.

OBJECTIVE

This study examines the efficacy and tolerability of the nonergot DA ropinirole for the long-term treatment of hyperprolactinemia.

METHODS

Twelve hyperprolactinemic women were treated with ropinirole in a 6-month, open-label, dose-escalation trial; 7 of the 12 continued treatment in an extension study for up to 17 months. Ropinirole doses were uptitrated to achieve normal prolactin (PRL) levels, restore menses, and eliminate galactorrhea.

RESULTS

Two of the 12 participants were DA naive; 6 of 12 were ergot DA intolerant; and 1 of 12 had known ergot DA resistance. Baseline PRL levels were 126.2 ± 41.4 ng/mL (SEM). Ropinirole was uptitrated from 0.125 to 0.25 mg/h to a median total daily dose (TDD) of 2 mg/d (1-4 mg/d [interquartile range]). PRL normalization was achieved in 50% of the participants (5 with microadenomas and 1 with idiopathic hyperprolactinemia) at a median effective TDD of 1 mg/d. Of the patients achieving PRL normalization, 83% were ergot DA intolerant. A persistent partial biochemical response (PRL reduction >50% from baseline) was achieved in 17% of the participants. During treatment, menses resumed in 67% of amenorrheic patients; galactorrhea resolved in 67%. Mild adverse effects were reported in 92% of participants; however, ropinirole was not discontinued because of intolerance even among the 50% of individuals with a prior history of ergot DA intolerance and resultant medication discontinuation.

CONCLUSION

These data demonstrate the efficacy and tolerability of ropinirole for the treatment of hyperprolactinemia in patients with microprolactinomas and idiopathic hyperprolactinemia and suggest ropinirole may represent a novel therapeutic alternative for treating hyperprolactinemic disorders in patients with ergot DA intolerance.

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.