Dopamine agonists in the treatment of prolactinoma: are they still first choice?

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.

Prolactin in Polycystic Ovary Syndrome: Metabolic Effects and Therapeutic Prospects

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine and metabolic disorder in premenopausal women, characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Patients frequently present comorbidities, including obesity, insulin resistance, and impaired glucose and lipid metabolism. The diverse clinical presentation may mimic various endocrine disorders, making the diagnosis challenging in some clinical circumstances. Prolactin (PRL) is a recommended biomarker in the initial diagnostic workup to rule out hyperprolactinemia (HPRL). The traditional role of PRL is linked to lactation and the reproductive system. Recent research highlights PRL's emerging role in metabolic homeostasis. PRL influences metabolism directly by interacting with the pancreas, liver, hypothalamus, and adipose tissue. Its influence on an individual's metabolism is intricately tied to its serum concentration. While deficient and very high levels of PRL can negatively affect metabolism, intermediate-normal to moderately high levels may promote metabolic health. In women with PCOS, PRL levels may be altered. Research results on different aspects of the relationship between PCOS and the impact of various levels of PRL on metabolic homeostasis are limited and inconsistent. In this narrative literature review, we comprehensively examined data on serum PRL levels in PCOS patients. We investigated the correlation between a favorable metabolic profile and serum PRL levels in this population. Furthermore, we explored the concept of beneficial PRL effects on metabolism and discussed the potential therapeutic application of dopamine agonists in PCOS treatment. Lastly, we emphasized several promising avenues for future research in this field.

Determinants of Surgical Remission in Prolactinomas: A Systematic Review and Meta-Analysis

OBJECTIVE

Prolactin-secreting tumors respond well to medical management, with a few patients requiring surgery. We conducted a systematic review and meta-analysis to study the determinants of surgical remission in these tumors.

METHODS

We searched PubMed to identify eligible studies reporting postoperative remission in patients treated with transsphenoidal surgery for prolactinoma. Primary outcomes included postoperative remission, follow-up remission, and recurrence. Postoperative and follow-up remission were defined as normoprolactinemia at <1 year and >1 year after operation, respectively. Recurrence was defined as hyperprolactinemia after initial normalization of prolactin levels. Odds ratios (ORs) were calculated, stratified by radiologic size, tumor extension, and tumor invasion, and analyzed using a random-effects model meta-analysis.

RESULTS

Thirty-five studies were included. Macroadenomas were associated with lower rates of postoperative remission (OR, 0.20; 95% confidence interval [CI], 0.16-0.24) and lower rates of remission at follow-up (OR, 0.11; 95% CI, 0.053-0.22). Postoperative remission was less likely in tumors with extrasellar or suprasellar extension (OR, 0.16; 95% CI, 0.06-0.43) and tumors with cavernous sinus invasion (OR, 0.03; 95% CI, 0.01-0.13). Female gender and absence of preoperative dopamine agonist treatment were also associated with higher remission rates. Across the included studies, there was considerable heterogeneity in each primary outcome (postoperative remission, I² = 94%; follow-up remission, I² = 86%; recurrence, I² = 68%).

CONCLUSIONS

Transsphenoidal surgery for prolactinomas may be particularly effective in small, noninvasive, treatment-naive tumors and may provide a viable first-line alternative to dopamine agonist therapy in such patients.

Recurrence of hyperprolactinemia following dopamine agonist withdrawal and possible predictive factors of recurrence in prolactinomas

BACKGROUND

The optimal duration of cabergoline (CAB) treatment of prolactinomas that minimizes recurrences is not well established. 2011 Endocrine Society Guidelines suggested that withdrawal may be safely undertaken after 2 years in patients achieving normoprolactinemia and tumor reduction.

MATERIALS

We analyzed 74 patients (mean age = 46.9 ± 14.4, M/F = 19/55, macro/micro = 18/56) bearing a prolactinoma divided in 3 groups: group A (23) treated for 3 years, group B (23) for a period between 3 and 5 years, and group C (28) for a period >5 years. CAB therapy was interrupted according to Endocrine Society Guidelines. Prolactin (PRL) levels were measured 3, 6, 12 and 24 months after withdrawal. Recurrence was defined with PRL levels ≥30 ng/ml.

RESULTS

Groups did not differ in pretreatment PRL levels (123.2 ± 112.1, 120.9 ± 123.8, 176.6 ± 154.0), pituitary deficit (4, 17, 17 %), mean CAB weekly dose (0.7 ± 0.4, 0.6 ± 0.3, 0.7 ± 0.4) and PRL levels before withdrawal (17.1 ± 19.6, 11.4 ± 8.8, 13.8 ± 13.5). Recurrence occurred within 12 months in 34 patients (45.9 %), without significant differences among groups. Neuroradiological evaluation showed a significantly higher presence of macroadenoma in group C (13, 17 and 39 %, respectively). Recurrence rate of hyperprolactinemia did not depend on sex, tumor size or CAB dose but it was significantly correlated with PRL levels at diagnosis and before withdrawal (p = 0.03). Finally, patients with pituitary deficit at diagnosis showed a significantly higher recurrence rate (p = 0.03).

CONCLUSIONS

The study provides additional evidence that prolonging therapy for more than 3 years does not reduce recurrence rate. In particular, recurrence risk was similar in micro- and macroadenomas, and higher in patients with pituitary deficits at diagnosis.

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.