Prolactinomas: evolution after menopause

Treatment of hyperprolactinemia in women: A Position Statement from the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and the Brazilian Society of Endocrinology and Metabolism (SBEM)

Dopamine agonists are the first line of treatment for patients with symptomatic hyperprolactinemia due to prolactinomas and in those with idiopathic hyperprolactinemia. Treatment with these agents is effective in 80%-90% of the cases. Infertility treatment of patients with hyperprolactinemia is also carried out with dopamine agonists, aiming for the normalization of prolactin levels. The risk of symptomatic growth of prolactinomas during pregnancy is dependent on the tumor's size, duration of previous treatments, and prolactin levels. Notably, the corresponding risk is relatively low in cases of microprolactinomas (<5%). Remission of hyperprolactinemia occurs in about 30% of the patients after drug treatment and may also occur after pregnancy and menopause. The use of some drugs, such as antidepressants and antipsychotics, is a frequent cause of hyperprolactinemia, and managing this occurrence involves unique considerations. This position statement by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) and Brazilian Society of Endocrinology and Metabolism (SBEM) addresses the recommendations for measurement of serum prolactin levels and the investigations of symptomatic and asymptomatic hyperprolactinemia and drug-induced hyperprolactinemia in women.

Prolactinoma in postmenopausal women: a systematic review

IMPORTANCE

Prolactinomas occurring during the reproductive period exhibit a characteristic behavior. There are, however, gaps in the literature regarding the behavior of these tumors after menopause.

OBJECTIVE

This study aimed to review and characterize the influence of menopause on prolactinoma behavior.

EVIDENCE REVIEW

A systematic review of observational prospective or retrospective studies and clinical trials on prolactinomas was conducted in two situations: tumors diagnosed in the reproductive period (before menopause), with follow-up in the postmenopausal period, or prolactinomas diagnosed in the postmenopausal period, without language or date restrictions. Data extracted from the articles included patient and tumor characteristics (prolactinoma type, previous treatment, symptoms, and serum prolactin [PRL] levels).

FINDINGS

This study included five studies comprising 180 participants. Prolactinomas diagnosed in women of reproductive age are treated with dopaminergic agonists (DAs), with indications of treatment withdrawal after menopause, exhibited stable tumor behavior and PRL levels. Considering the diagnosis during the postmenopausal period, macroprolactinomas were more prevalent and showed tumor shrinkage when DAs were used. Cabergoline, the most commonly used drug, lowers PRL levels and reduces symptoms associated with adenoma.

CONCLUSIONS AND RELEVANCE

Microadenomas diagnosed before menopause can be followed up without treatment. Prolactinomas diagnosed after menopause are typically macroadenomas. Cabergoline remains the treatment of choice in the presence of clinical or compressive symptoms. We recommend at least one annual follow-up for such patients.

Approach to the Patient With Prolactinoma

Prolactinomas are the most common pituitary tumor histotype, with microprolactinomas being prevalent in women and macroprolactinomas in men. Hyperprolactinemia is among the most common causes of hypogonadotropic hypogonadism in both sexes, prompting medical advice for hypogonadism (infertility, oligo-amenorrhea, impotence, osteoporosis/osteopenia) in both sexes, and for signs and symptoms of mass effects (hypopituitarism, visual loss, optic chiasm compression, cranial nerve deficits, headaches) predominantly in men. Diagnostic workup involves a single prolactin measurement and pituitary imaging, but some laboratory artifacts (ie, the "hook effect" and macroprolactin) can complicate or delay the diagnosis. The treatment of choice for prolactinomas is represented by dopamine agonists, mainly cabergoline, which are able to induce disease control, restore fertility in both sexes, and definitively cure one-third of patients, thus permitting treatment discontinuation. Pregnancy and menopause may promote spontaneous prolactin decline and anticipate cabergoline discontinuation in women. Surgery and/or radiotherapy are indicated in case of resistance to cabergoline not overcome by the increase in drug dose up to the maximally tolerated or the patient's personal choice of surgery. The evidence of resistance to cabergoline in invasive and proliferative tumors may indicate biological aggressiveness, thus requiring alternative therapeutic approaches mainly based on temozolomide use as monotherapy or combined with radiotherapy. In uncontrolled patients, new medical approaches (alternative hormonal treatments, cytotoxic drugs, peptide receptor radionuclide therapy, mTOR/Akt inhibitors, tyrosine kinase inhibitors, or immunotherapy) may be offered but the experience collected to date is still very scant. This article reviews different facets of prolactinomas and discusses approaches to the condition in more common clinical situations.

Are dopamine agonists still the first-choice treatment for prolactinoma in the era of endoscopy? A systematic review and meta-analysis

Background

For prolactinoma patients, dopamine agonists (DAs) are indicated as the first-line treatment and surgery is an adjunctive choice. However, with the development of surgical technique and equipment, the effect of surgery has improved. The aim of this study was to assess the efficacy and safety of surgery versus DAs in patients with different types of prolactinomas.

Methods

A systematic search of literature using Web of Science, PubMed, Cochrane Library, and Clinical Trial databases was conducted until July 12, 2019. Prolactinoma patients treated with DAs (bromocriptine or cabergoline) or surgery (microscopic or endoscopic surgery) were included. Outcomes included the biochemical cure rate, recurrence rate, prolactin level, improvement rates of symptoms, and incidence rates of complications. A random-effects model was used to pool the extracted data. Qualitative comparisons were conducted instead of quantitative comparison.

Results

DAs were better than surgery in terms of the biochemical cure rate (0.78 versus 0.66), but surgery had a much lower recurrence rate (0.19 versus 0.57). Full advantages were not demonstrated in improvement rates of symptoms and incidence rates of complications with both treatment options. In microprolactinoma patients, the biochemical cure rate of endoscopic surgery was equal to the average cure rate of DAs (0.86 versus 0.86) and it surpassed the biochemical cure rate of bromocriptine (0.86 versus 0.76). In macroprolactinoma patients, endoscopic surgery was slightly higher than bromocriptine (0.66 versus 0.64) in terms of the biochemical cure rate.

Conclusion

For patients with clear indications or contraindications for surgery, choosing surgery or DAs accordingly is unequivocal. However, for patients with clinical equipoise, such as surgery, especially endoscopic surgery, in microprolactinoma and macroprolactinoma patients, we suggest that neurosurgeons and endocrinologists conduct high-quality clinical trials to address the clinical equipoise quantitatively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41016-022-00277-1.

Oral Contraceptive and Menopausal Hormone Therapy Use and Risk of Pituitary Adenoma: Cohort and Case-Control Analyses

CONTEXT

No prospective epidemiologic studies have examined associations between use of oral contraceptives (OCs) or menopausal hormone therapy (MHT) and risk of pituitary adenoma in women.

OBJECTIVE

Our aim was to determine the association between use of OC and MHT and risk of pituitary adenoma in two separate datasets.

METHODS

We evaluated the association of OC/MHT with risk of pituitary adenoma in the Nurses' Health Study and Nurses' Health Study II by computing multivariable-adjusted hazard ratios (MVHR) of pituitary adenoma by OC/MHT use using Cox proportional hazards models. Simultaneously, we carried out a matched case-control study using an institutional data repository to compute multivariable-adjusted odds ratios (MVOR) of pituitary adenoma by OC/MHT use.

RESULTS

In the cohort analysis, during 6 668 019 person-years, 331 participants reported a diagnosis of pituitary adenoma. Compared to never-users, neither past (MVHR = 1.05; 95% CI, 0.80-1.36) nor current OC use (MVHR = 0.72; 95% CI, 0.40-1.32) was associated with risk. For MHT, compared to never-users, both past (MVHR = 2.00; 95% CI, 1.50-2.68) and current use (MVHR = 1.80; 95% CI, 1.27-2.55) were associated with pituitary adenoma risk, as was longer duration (MVHR = 2.06; 95% CI, 1.42-2.99 comparing more than 5 years of use to never, P trend = .002). Results were similar in lagged analyses, when stratified by body mass index, and among those with recent health care use. In the case-control analysis, we included 5469 cases. Risk of pituitary adenoma was increased with ever use of MHT (MVOR = 1.57; 95% CI, 1.35-1.83) and OC (MVOR = 1.27; 95% CI, 1.14-1.42) compared to never.

CONCLUSION

Compared to never use, current and past MHT use and longer duration of MHT use were positively associated with higher risk of pituitary adenoma in 2 independent data sets. OC use was not associated with risk in the prospective cohort analysis and was associated with only mildly increased risk in the case-control analysis.

Hyperprolactinemia after menopause: Diagnosis and management

Most prolactinomas are diagnosed in women of reproductive age and are generally microadenomas. Prolactinomas diagnosed in postmenopausal women are less common and are not usually associated with the typical syndrome induced by prolactin excess, including infertility and oligo-amenorrhea. This implies that the diagnosis of prolactinomas after menopause may be delayed and require greater clinical effort. Limited data are available on the management and prognosis of prolactinomas in postmenopausal women. However, the physiologic decline of prolactin levels during menopause and the lack of fertility concerns, which represent specific indications for medical treatment with dopamine agonists, might require a careful reassessment of therapeutic management in such patients. Postmenopausal women with microprolactinoma may be successfully withdrawn from medical therapy with dopamine agonists, whereas in those with macroprolactinomas greater caution is advisable before dopamine agonists are discontinued, considering the potential, although rare, tumor enlargement. This review focuses on the diagnostic challenges and therapeutic management of prolactinomas in postmenopausal women.

Do nothing but observe microprolactinomas: when and how to replace sex hormones?

Hyperprolactinemia is associated with suppression of the hypothalamic- pituitary-gonadal axis and consequent hypogonadism, manifesting loss of libido, infertility and osteoporosis long-term in both male and female patients, with associated menstrual irregularities, amenorrhea and galactorrhea in women and erectile dysfunction in men. The primary goals of therapy in patients harboring prolactinoma are control of tumor size and normalization of serum PRL, with restoration of gonadal and sexual function and fertility. Clinical manifestations of hypogonadism have variable consequences depending on the age and sex of the patient and desire for fertility. Careful consideration of clinical consequences of hyperprolactinemia in relation to age and sex should help guide therapeutic decision making. Another important consideration in attaining our treatment goals in patients harboring microprolactinomas, is the observation that greater than 90% of microprolactinomas do not enlarge, when followed for 10 years. Treatment options for the management of microprolactinomas include observation alone, with monitoring of serum prolactin levels every 6-12 months, vs initiation of dopamine agonist therapy vs gonadal steroid hormone replacement (using the oral contraceptive or other combination estrogen and progesterone replacement regimens in females or testosterone replacement therapy in males). In the present review, current data related to clinical consequences of microprolactinomas and treatment outcomes at different stages in the lifespan are reviewed, with a suggested algorithm as to whether to treat or not, and an appropriate therapeutic regimen to institute.

Prolactinomas and menopause: any changes in management?

PURPOSE

Treatment goals in prolactinomas are to correct hypogonadism, restore fertility and control tumor mass in case of macroadenomas. According to current guidelines, medical treatment of asymptomatic postmenopausal women is not indicated. The purpose of this study was to review the current literature pertaining to biological behavior of prolactinomas during menopause, likelihood of successful dopamine agonist withdrawal during this period and possible prolactin-mediated increased morbidity that could modify current management.

METHODS

A comprehensive literature search including papers published until July 2019 was conducted using PubMed and Medline databases.

RESULTS

Women with prolactinomas entering menopause have a higher chance of prolactin normalization of treatment compared with women in their reproductive years. Although most prolactin secreting adenomas diagnosed during menopause are large, they respond well to dopamine agonist treatment. Data directly linking hyperprolactinemia with an increased risk of cancer and cardiovascular and metabolic morbidity are inconsistent. There is no data indicating that correction of hyperprolactinemia improves clinical outcomes in asymptomatic patients bearing microadenomas.

CONCLUSION

There is no evidence that justifies changing current recommendations to withhold medical treatment of microprolactinomas in asymptomatic post-menopausal women. Macroprolactinoma patients should be treated according to standard clinical practice.

Dopamine agonists in prolactinomas: when to withdraw?

Dopamine agonists (DAs) are well recognized as the first-line therapy for prolactinomas due to their efficacy in achieving tumoral shrinkage and normoprolactinemia. However, it remains to be established the best timing to withdraw DAs and in which patients this should be attempted. Studies in the 1980s, mainly using bromocriptine, started to defy the concept that DAs should be regarded as a lifelong therapy considering that sustained normoprolactinemia was attained in a small subset of patients after drug withdrawal. The introduction of the more effective agent cabergoline led to an increase in the percentages of remission. The most recent meta-analysis on the topic stated than remission rates after withdrawal can range from 15% in macroprolactinoma patients treated with bromocriptine to 41% in those with microprolactinomas previously treated with cabergoline. When more stringent criteria were applied before attempting withdrawal, sustained remission ensued in more than 50% of the individuals. Treatment duration for more than 24 months, the achievement of normoprolactinemia, marked reduction (≥ 50%) in tumoral size and DAs tapering till a low maintenance dose (e.g. cabergoline 0.5 mg/week) have been the most consistently identified predictors of success. In addition, a growing amount of evidence suggests that the post-pregnancy/breastfeeding period and menopause are reasonable timings to re-access the need for continuing DAs therapy. Considering that the achievement of sustained normoprolactinemia is still far from being universal after the withdrawal, even in highly selected cohorts, future larger prospective studies should continue to address this issue.

Cabergoline Withdrawal Before and After Menopause: Outcomes in Microprolactinomas

Natural course of prolactinomas after menopause is not fully elucidated. The aim of this study was to compare recurrence rate after cabergoline withdrawal in premenopausal vs. postmenopausal women with microprolactinoma. Sixty-two women with microprolactinoma treated with cabergoline for at least 1 year and followed for 2 years after drug withdrawal were retrospectively selected. Patients were divided into two groups: 48 patients stopped cabergoline before menopause ("PRE" group), while 14 after menopause ("POST" group). Recurrence was defined by prolactin levels above normal, confirmed on two occasions. Overall, 39/62 women relapsed. Patients who relapsed apparently had higher prolactin before withdrawal (median 216.2, range 21.2-464.3 mIU/L) compared with those in long-term remission (94.3, 29.7-402.8 mIU/L; p < 0.05), and the risk of recurrence seemed lower in POST women (4/14, 29%) than in PRE ones (35/48, 73%, p < 0.005, OR 0.149, 95% CI 0.040-0.558). However, none of the factors (prolactin before withdrawal, menopausal status, treatment duration, complete adenoma regression) showed a correlation with recurrence risk in multivariate analysis. The best strategy able to optimize CBG treatment and withdrawal's outcomes is still to be defined in microprolactinomas. Postmenopausal status cannot reliably predict long-term remission, and follow-up is needed also in women of this age.