The effect of the menopause on prolactin levels in patients with hyperprolactinaemia

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.

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.

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.

Italian Association of Clinical Endocrinologists (AME) and International Chapter of Clinical Endocrinology (ICCE). Position statement for clinical practice: prolactin-secreting tumors

Prolactinomas are the most frequent pituitary adenomas. Prolactinoma may occur in different clinical settings and always require an individually tailored approach. This is the reason why a panel of Italian neuroendocrine experts was charged with the task to provide indications for the diagnostic and therapeutic approaches that can be easily applied in different contexts. The document provides 15 recommendations for diagnosis and 54 recommendations for treatment, issued according to the GRADE system. The level of agreement among panel members was formally evaluated by RAND-UCLA methodology. In the last century, prolactinomas represented the paradigm of pituitary tumors for which the development of highly effective drugs obtained the best results, allowing to avoid neurosurgery in most cases. The impressive improvement of neurosurgical endoscopic techniques allows a far better definition of the tumoral tissue during surgery and the remission of endocrine symptoms in many patients with pituitary tumors. Consequently, this refinement of neurosurgery is changing the therapeutic strategy in prolactinomas, allowing the definitive cure of some patients with permanent discontinuation of medical therapy.

Dopamine agonist therapy for prolactinomas: do we need to rethink the place of surgery in prolactinoma management?

The current treatment paradigm for prolactinomas involves dopamine agonist (DA) therapy as the first-line treatment, with surgical resection reserved for cases where there is DA failure due to resistance or intolerance. This review highlights how DA therapy can be optimised to overcome its increasingly recognised pitfalls, whilst also addressing the potential for expanding the use of surgery in the management of prolactinomas. The first part of the review discusses the limitations of DA therapy, namely: DA resistance; common DA side effects; and the rare but serious DA-induced risks of cardiac valvulopathy, impulse control disorders, psychosis, CSF rhinorrhoea and tumour fibrosis. The second part of the review explores the role of surgery in prolactinoma management with reference to its current second-line position and recent calls for surgery to be considered as an alternative first-line treatment alongside DA therapy. Randomised trials comparing medical vs surgical therapy for prolactinomas are currently underway. Pending these results, a low surgical threshold approach is herein proposed, whereby DA therapy remains the default treatment for prolactinomas unless there are specific triggers to consider surgery, including concern regarding DA side effects or risks in vulnerable patients, persistent and bothersome DA side effects, emergence of any serious risks of DA therapy, expected need for long-term DA therapy, as well as the traditional indications for surgery. This approach should optimise the use of DA therapy for those who will most benefit from it, whilst instituting surgery early in others in order to minimise the cumulative burden of prolonged DA therapy.

Hyperprolactinemia in the postmenopause: versions and contraversions

The prevalence of hyperprolactinemia in postmenopausal women is unknown and has been estimated as infrequent by many studies. Prolactinomas found after menopause are usually macroadenomas and remain unrecognized for a long time due to atypical clinical signs or their absence. The growth potential of prolactinomas persists after menopause, most of them are invasive and accompanied by high prolactin levels. Treatment with dopamine agonists is usually long-term, the goals of which are to reduce tumor size, normalize prolactin levels and the negative effects of hyperprolactinemia. Treatment with cabergoline makes it possible to achieve remission of the disease in the first years after discontinuation, however, the proportion of relapses in postmenopausal women increases 5 years after discontinuation of the drug. Remission of prolactinomas is not evident in postmenopausal women. The modern management of patients with prolactinoma and/or hyperprolactinemia does not have clear positions in the postmenopausal period. Controversial issues remain: an ambiguous relationship between prolactin levels and breast cancer, there are no convincing conclusions on the improvement of bone mineral density and/or a decrease in the risk of fractures with normalization of prolactin levels, there are no data on metabolic parameters after the end of treatment with dopamine agonists, conflicting information about the relationship of prolactin levels and the severity of the manifold manifestations of the climacteric syndrome. The use of estrogen-progestin drugs in women with hyperprolactinemia/prolactinomas is also not well understood. Thus, the problem of hyperprolactinemia in the perimenopausal and postmenopausal period is underestimated and requires additional research, as well as the development of diagnostic and therapeutic strategies for potential benefits in terms of weight loss, improving insulin sensitivity, reducing the risk of fractures, maintaining sexuality and psycho-emotional well-being.

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.

Antipsychotic-induced Hyperprolactinemia in aging populations: Prevalence, implications, prevention and management

This paper reviews the prevalence, implications, prevention and management of antipsychotic-induced hyperprolactinemia in aging populations. Antipsychotics are indicated mainly for the treatment of psychotic illness but are also used in other conditions. Complications induced by antipsychotics increase with age, due to age-related changes in drug metabolism and excretion. Almost all antipsychotics lead to hyperprolactinemia by blocking dopamine D2 receptors in the anterior pituitary gland, which counteracts dopamine's inhibitory action on prolactin secretion. The main findings of this narrative review are that, though many of the known side effects of high prolactin levels lose their salience with age, the risk of exacerbating osteoporosis remains critical. Methods of preventing antipsychotic-induced hyperprolactinemia in older individuals include using antipsychotic medication (AP) as sparingly as possible and monitoring AP serum levels, regularly measuring prolactin levels, closely monitoring bone density, treating substance abuse, and teaching patients stress management techniques. When hyperprolactinemia symptoms cannot be otherwise managed, adjunctive drugs are available. Potential helpful adjuncts are: dopamine agonists, antipsychotics with partial agonist properties (e.g. aripiprazole), selective estrogen receptor modulators, and metformin. Because a gold standard for prevention/treatment has not been established, clinical decisions need to be made based on safety and individual circumstance.

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.

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.

Epidemiology and Management Challenges in Prolactinomas

Clinically relevant pituitary adenomas are present in about 1 per 1,000 of the general population and prolactinomas are by far the most common clinical subtype of pituitary adenomas. Usually prolactinomas affect premenopausal women and present with typical symptoms of menstrual disturbance and/or galactorrhea. They are generally managed with dopamine agonists to restore fertility and to control symptoms and tumor size. In a subset of prolactinomas, however, management remains challenging. Studies in recent years have identified the factors related to dopamine agonist resistance, such as male sex, genetic features, and aggressive tumor behavior. Certain other patient groups represent particular challenges for management, such as pediatric patients and pregnant women. Treatment with dopamine agonists is usually safe and effective, and adverse effects such as clinically relevant cardiac valvular complications and impulse control disorders may occur in isolated instances. A number of important disease characteristics of prolactinomas remain to be explained, such as the difference in sex prevalence before and after menopause, the higher prevalence of macroadenomas in older males, and the biochemical mechanisms of resistance to dopaminergic agonists.

Hyperprolactinemia/Prolactinomas in the Postmenopausal Period: Challenges in Diagnosis and Management

Hyperprolactinemia is not a common finding in postmenopausal women. Prolactinomas detected after menopause are usually macroadenomas. Due to atypical clinical features they may remain unrecognized for a long period of time. Interestingly the growth potential of prolactinomas remains after menopause. Most tumors are invasive and present with high prolactin levels. They respond to medical treatment with dopamine agonists in terms of prolactin normalization, tumor shrinkage, and improvement in pituitary function. Treatment with dopamine agonists is usually long term. Reducing doses of cabergoline to the lowest that keeps prolactin levels normal prior to withdrawal is proposed to patients with macroprolactinomas who normalize prolactin after > 5 years of treatment and who do not have cavernous sinus invasion. Cabergoline can achieve a high percentage of remission maintenance in the first years after withdrawal. However, the percentage of relapse-free patients 5 years after withdrawal is significantly lower. Besides recurrent hyper-prolactinemia in a subgroup of macroprolactinomas after a long-interval tumor regrowth may be detected. Menopause cannot ensure remission of the tumor so long-term surveillance is suggested. In patients with microadenomas data on long-term remission rates (normalization of prolactin and disappearance of the tumor) after suspension of treatment with dopamine agonists are highly variable. The current strategy for microprolactinomas is not to treat hyperprolactinemia in menopause if it recurrs after discontinuation of dopamine agonists. This is based on: (1) reports that elevated prolactin levels may normalize in some women after menopause, (2) the fact that the association between prolactin levels and breast cancer is inconsistent in postmenopausal women, (3) the lack of clinical evidence that normalization of prolactin levels in postmenopausal women improves bone mineral density or reduces the risk of fracture, and (4) the fact that, concerning the metabolic syndrome, no data are available on metabolic parameters after suspension of treatment with dopamine agonists. For a change in strategy, i.e., for the potential benefits from treatment of hyperprolactinemia in the postmenopausal period with dopamine agonists concerning weight loss, improved insulin sensitivity, decreased fracture risk, and improved sexuality, more evidence is needed.

Impact of menopause on outcomes in prolactinomas after dopamine agonist treatment withdrawal

OBJECTIVE

Discontinuation of dopamine agonist (DA) treatment in women with prolactinoma after menopause is a potential approach; studies systematically assessing long-term outcomes are lacking. Our aim was to investigate the natural history of prolactinoma in this group.

DESIGN/PATIENTS

Retrospective cohort study of women with prolactinoma diagnosed before menopause and who after menopause were not on DA.

RESULTS

Thirty women were included. Twenty-eight received DA (median duration 18 years, median age at DA withdrawal 52 years). At last assessment (median follow-up 3 years) and compared with values 6-12 months after stopping DA, Prolactin (PRL) increased in 15%, decreased but not normalized in 33% and was normal in 52%; PRL levels or visible adenoma on imaging before DA withdrawal, treatment duration and presence of macro-/microadenoma at diagnosis were not predictors of normoprolactinaemia at last review, whereas PRL values 6-12 months after stopping DA were. Adenoma regrowth was detected in 2/27 patients (7%), who showed gradual increase in PRL. Comparison with 28 women who had DA withdrawal before their menopause revealed lower risk of hyperprolactinaemia recurrence in the postmenopausal group (HR:0.316, 95% CI: 0.101-0.985, P < .05). Two women with microprolactinoma diagnosed in perimenopausal period had not been offered DA; PRL decreased (but not normalized) during observation of 1 and 8 years.

CONCLUSIONS

Prolactin normalized over time in nearly half of the women and serum PRL 6-12 months after DA withdrawal is useful predictor. Nonetheless, 7% of the patients demonstrated adenoma regrowth which, given the life expectancy postmenopause, necessitate regular monitoring of the cases with persistent hyperprolactinaemia.

Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

Prolactinoma through the female life cycle

Prolactinomas are the most common secretory pituitary adenoma. They typically occur in women in the 3rd-6th decade of life and rarely in the pediatric population or after menopause. Most women present with irregular menses and/or infertility. Dopamine (DA) agonists, used in their treatment, are safe during pregnancy, but in most cases are discontinued at conception with close monitoring for signs or symptoms of tumor growth. Breastfeeding is safe postpartum, provided there was no significant growth during pregnancy. Some women will experience normalization of prolactin levels postpartum. Menopause may also decrease prolactin levels and even those with macroprolactinomas may consider discontinuing their DA agonist with close follow-up. Prolactinomas may be associated with decreased quality of life scores in women, and play a role in bone health and cardiovascular risk factors. This review discusses the current literature and clinical understanding of prolactinomas throughout the entirety of the female life cycle.

Prolactinomas diagnosed in the postmenopausal period: Clinical phenotype and outcomes

OBJECTIVE

Most prolactinomas in females are diagnosed during the reproductive age, and the majority are microadenomas. Prolactinomas detected in the postmenopausal period are less common with limited published data on their presentation and prognosis. Our objective was to assess the presenting clinical, biochemical and imaging findings, as well as the outcomes of women diagnosed with a prolactinoma in the postmenopausal period.

DESIGN AND METHODS

We undertook a retrospective cohort study of women diagnosed with prolactinoma after menopause and followed up in a large UK pituitary centre. Information on presentation, management and outcomes was collected.

RESULTS

Seventeen women with a median age at diagnosis of 63 years (range 52-78) were identified. Headaches and/or visual deterioration were the most commonly reported complaints at detection of the adenoma (47%). Acute pituitary apoplexy was diagnosed at presentation or during follow-up in 18% of the cases. The median serum prolactin was 12 364 mU/L (range 2533-238 479). Macroprolactinomas comprised 94% of the tumours, and 88% of them had supra/parasellar extension. All patients with macroprolactinoma were offered dopamine agonist, and normal prolactin was achieved in 94% of them (median follow-up 91.5 months). Adenoma shrinkage was observed in all women. Improvement or resolution of visual disturbances documented at presentation was observed in 86% of cases.

CONCLUSIONS

The clinical phenotype of prolactinomas diagnosed in the postmenopausal period is characterized by dominance of macroadenomas, with frequent supra/parasellar extension and a relative high rate of acute pituitary apoplexy. In this group of patients, the response of the macroadenomas to dopamine agonists is good.

Hyperprolactinaemia - a problem in patients from the reproductive period to the menopause

Hyperprolactinaemia especially affects women in reproductive age (90/100,000) but also often is diagnosed in menopause age and leads to disturbances in functioning of LH-RH neurons and, as a consequence, to a decrease of FSH and LH, which causes inhibition of oestradiol production. Prolactin is a peptide hormone, phylogenetically one of the oldest, stimulating cells of various organs, which is produced and secreted mainly by lactotrophic acidophilic cells of the anterior lobe of the pituitary. It influences the increase in the mass of the mammary glands, and stimulation and maintenance of lactation after delivery. There are a number of factors apart of pregnancy, delivery, and lactation than can influence secretion of the hormone in other physiological and pathological circumstances, like high-protein diet, stress, REM sleep, or neoplastic tumours, inflammatory diseases, chronic systematic diseases, thyroid hormonal changes, and drug intake. The purpose of this review is to summarise the current knowledge regarding the proper diagnosis and possible influence of hyperprolactinaemia on fertility and menopause symptoms and current treatment methods.

Prolactinomas: evolution after menopause

OBJETIVE

The aim was to assess the evolution of tumor size and prolactin (PRL) levels in patients with micro and macroprolactinomas diagnosed and treated with dopamine agonists during fertile age, and the effects of suspension of drugs after menopause.

SUBJECTS AND METHODS

Retrospective study, 29 patients with prolactinomas, 22 microadenomas and 7 macroadenomas, diagnosed during their fertile age were studied in their menopause; treatment was stopped in this period. Age at menopause was 49 ± 3.6 years. The average time of treatment was 135 ± 79 months. The time of follow-up after treatment suspension was 4 to 192 months. Results: Pre-treatment PRL levels in micro and macroadenomas were 119 ± 57 ng/mL and 258 ± 225 ng/mL, respectively. During menopause after treatment suspension, and at the latest follow-up: in microadenomas PRL levels were 23 ± 13 ng/mL and 16 ± 5.7 ng/mL, respectively; in macroadenomas, PRL levels were 20 ± 6.6 ng/mL 5t5and 25 ± 18 ng/mL, respectively. In menopause after treatment suspension, the microadenomas had disappeared in 9/22 and had decreased in 13/22. In the group of patients whose tumor had decreased, in the latest follow-up, tumors disappeared in 7/13 and remained unchanged in 6/13. In macroadenomas, after treatment suspension 3/7 had disappeared, 3/7 decreased and 1/7 remained unchanged. In the latest control in the 3 patients whose tumor decreased, disappeared in 1/3, decreased in 1/3 and there was no change in the remaining.

CONCLUSIONS

Normal PRL levels and sustained reduction or disappearance of adenomas were achieved in most of patients, probably due to the decrease of estrogen levels. Dopamine agonists might be stopped after menopause in patients with prolactinomas.

Treatment of hyperprolactinemia in post-menopausal women: pros

The incidence of hyperprolactinemia in women peaks during the 3rd-4th decade and then greatly decreases after the menopause. Apart from the effects on the hypothalamic-pituitary-gonadal axis, prolactin can act directly on bone metabolism. Hyperprolactinemia is a recognized cause of secondary osteoporosis, and treatment with dopamine agonists can lead to improved BMD. Moreover, hyperprolactinemia has been linked to weight gain and insulin resistance, which can be ameliorated following medical treatment. Although relatively rare, prolactinomas can be observed in post-menopausal women and are frequently large and invasive; dopamine agonists appear to be as effective in these patients as in younger women to induce reduction of prolactin levels and tumour shrinkage. Here, we review data potentially favouring medical treatment with dopamine agonists in post-menopausal women diagnosed with hyperprolactinemia.

Hyperprolactinemia and prolactinoma

Prolactinomas are the most frequent pituitary adenomas. In patients with prolactinomas the primary cause of hyperprolactinemia is excessive and autonomic production of prolactin by lactotroph cells. In other conditions, except in case of macroprolactinemia, hyperprolactinemia is secondary to circumstances that stimulate secretion of prolactin by intrinsically normal lactotroph cells, or, rarely, that are the result of decreased clearance of prolactin. In general, cabergoline is the preferred treatment for micro- and macroprolactinomas, because it is more effective with respect to normalization of prolactin levels and reduction of prolactinoma size and because it has fewer side-effects compared to bromocriptine. Recently, it has been suggested that a standardized, individualized, stepwise, dose-escalating regimen of cabergoline may normalize prolactin levels and reduce prolactinoma size in patients who were otherwise considered to be dopamine agonist resistant. In general, the cardiac adverse effects of dopamine agonists reported in Parkinson's disease are not of clinical concern in the treatment of prolactinomas, which are treated with much lower doses. Nonetheless, there is uncertainty with respect to the dose and duration of cabergoline treatment, which requires echocardiographic follow-up. Although withdrawal of dopamine agonists may be considered in patients with prolactinomas well controlled by dopamine agonists, especially in postmenopausal women, recurrence of signs and symptoms may occur in a considerable portion of patients.

[Clinical guidelines for diagnosis and treatment of prolactinoma and hyperprolactinemia]

OBJECTIVE

To provide practical and up to date recommendations for evaluation, differential diagnosis, and treatment of prolactinoma and hyperprolactinemia in various clinical settings.

PARTICIPANTS

Members of the Neuroendocrinology Working Group of the Spanish Society of Endocrinology.

METHODS

Recommendations were formulated according to the Grading of Recommendations, Assessment, Development, and Evaluation system (GRADE) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in Medline (Pubmed) for each subject, and authors' considerations were added in areas where the literature provided scarce evidence. Finally, recommendations were jointly discussed by the Working Group.

CONCLUSIONS

The document provides evidence-based practical and updated recommendations for diagnosis and management of hyperprolactinemia and prolactinoma, including drug-induced hyperprolactinemia, treatment options for prolactinoma (drugs, surgery, and radiotherapy), prolactinoma in pregnancy, adverse effects of dopaminergic agents, and drug-resistant and malignant prolactinomas.

Treatment of hyperprolactinemia: a systematic review and meta-analysis

BACKGROUND

Hyperprolactinemia is a common endocrine disorder that can be associated with significant morbidity. We conducted a systematic review and meta-analyses of outcomes of hyperprolactinemic patients, including microadenomas and macroadenomas, to provide evidence-based recommendations for practitioners. Through this review, we aimed to compare efficacy and adverse effects of medications, surgery and radiotherapy in the treatment of hyperprolactinemia.

METHODS

We searched electronic databases, reviewed bibliographies of included articles, and contacted experts in the field. Eligible studies provided longitudinal follow-up of patients with hyperprolactinemia and evaluated outcomes of interest. We collected descriptive, quality and outcome data (tumor growth, visual field defects, infertility, sexual dysfunction, amenorrhea/oligomenorrhea and prolactin levels).

RESULTS

After review, 8 randomized and 178 nonrandomized studies (over 3,000 patients) met inclusion criteria. Compared to no treatment, dopamine agonists significantly reduced prolactin level (weighted mean difference, -45; 95% confidence interval, -77 to -11) and the likelihood of persistent hyperprolactinemia (relative risk, 0.90; 95% confidence interval, 0.81 to 0.99). Cabergoline was more effective than bromocriptine in reducing persistent hyperprolactinemia, amenorrhea/oligomenorrhea, and galactorrhea. A large body of noncomparative literature showed dopamine agonists improved other patient-important outcomes. Low-to-moderate quality evidence supports improved outcomes with surgery and radiotherapy compared to no treatment in patients who were resistant to or intolerant of dopamine agonists.

CONCLUSION

Our results provide evidence to support the use of dopamine agonists in reducing prolactin levels and persistent hyperprolactinemia, with cabergoline proving more efficacious than bromocriptine. Radiotherapy and surgery are useful in patients with resistance or intolerance to dopamine agonists.

Update on the withdrawal of dopamine agonists in patients with hyperprolactinemia

PURPOSE OF REVIEW

Despite the widespread use of dopamine agonists for patients with prolactinomas and symptomatic idiopathic hyperprolactinemia for many decades, the optimal treatment strategy and duration of treatment is still not evident. This review highlights the effects of dopamine agonist withdrawal in patients with idiopathic hyperprolactinemia and prolactinomas in detail, including the factors influencing the success of treatment outcome.

RECENT FINDINGS

It appeared that a subgroup of patients with a high likelihood of achieving remission could be identified on clinical criteria, which were incorporated in the Pituitary Society 2006 consensus guidelines. A recent systematic review and meta-analysis, however, demonstrated that the pooled proportion of patients with persisting normoprolactinemia after dopamine agonist withdrawal was only 21%, with a higher treatment success in idiopathic hyperprolactinemia (32%), compared with both microprolactinomas (21%) and macroprolactinomas (16%). In a random effects meta-regression, longer treatment duration was associated with treatment success. The probability of treatment success was highest when cabergoline was used for at least 2 years. Recommendations have now been adjusted accordingly in the 2011 Endocrine Society Practical guideline.

SUMMARY

Hyperprolactinemia will recur after dopamine agonist withdrawal in a considerable proportion of patients, but not all dopamine agonists have comparable efficacy. The optimal withdrawal strategy still needs to be determined in further studies.

Medical treatment of prolactinomas

Prolactinomas, the most prevalent type of neuroendocrine disease, account for approximately 40% of all pituitary adenomas. The most important clinical problems associated with prolactinomas are hypogonadism, infertility and hyposexuality. In patients with macroprolactinomas, mass effects, including visual field defects, headaches and neurological disturbances, can also occur. The objectives of therapy are normalization of prolactin levels, to restore eugonadism, and reduction of tumor mass, both of which can be achieved in the majority of patients by treatment with dopamine agonists. Given their association with minimal morbidity, these drugs currently represent the mainstay of treatment for prolactinomas. Novel data indicate that these agents can be successfully withdrawn in a subset of patients after normalization of prolactin levels and tumor disappearance, which suggests the possibility that medical therapy may not be required throughout life. Nevertheless, multimodal therapy that involves surgery, radiotherapy or both may be necessary in some cases, such as patients who are resistant to the effects of dopamine agonists or for those with atypical prolactinomas. This Review reports on efficacy and safety of pharmacotherapy in patients with prolactinomas.

Treatment for prolactinomas and hyperprolactinaemia: a lifetime approach

BACKGROUND

Prolactinomas are the most common hormone-secreting pituitary tumours and are amenable to medical therapy with dopamine agonists. Indication for treatment will most commonly result from hypogonadism, infertility or symptoms related to tumour size. Thus, both diagnosis and treatment will essentially depend on the patients' stage of life, namely prepubertal, reproductive or postreproductive stage. This review will focus on a lifespan-dependent diagnosis and treatment for prolactinoma and hyperprolactinaemia.

METHODS

PubMed, the Cochrane Library, the Web of Science and EMBASE were searched electronically. No restriction was made with respect to language. Relevant current articles will be included in this review.

RESULTS

Prevalence of prolactinomas and clinical symptoms are age group-specific, and treatment of first choice is dopamine agonists over the whole lifespan. Open questions in the treatment for hyperprolactinaemia include optimal choice and duration of pharmacological treatment. In addition, concerns have been raised on the safety of dopamine agonists since a reported association of valvular heart disease with dopaminergic treatment in patients with Parkinson's disease.

CONCLUSIONS

Clinical presentation and consequences of hyperprolactinaemia and prolactinoma will differ in the specific stages of reproductive life and require an adequate lifetime-dependent diagnostic and therapeutic approach.

Pituitary tumours: the prolactinoma

This review focus on the epidemiology, diagnosis and treatment of prolactinomas. In particular, attention was given to recent data showing a high prevalence of these tumours in the general population, 3-5 times higher than previously reported. The diagnosis of hyperprolactinaemia has been simplified in recent years, and only prolactin (PRL) assay and magnetic resonance imaging of the sella are required. Nonetheless, macroprolactinaemia should be assessed in patients with hyperprolactinaemia in the absence of clinical symptoms of elevated PRL levels. The recent evidence that medical therapy with dopamine agonists should be continued lifelong has been confirmed by several studied. The patients achieving disappearance of the tumours and suppression of PRL levels during treatment are those showing the highest likelihood to have persistent remission of hyperprolactinaemia after treatment withdrawal.

[Treatment of pituitary adenomas]

According to epidemiological studies, the prevalence of pituitary adenomas is 16.5% and the majority of them are "incidentalomas". The symptoms of pituitary disorders are often non-specific; disturbances of pituitary function, compression symptoms, hypophysis apoplexy or accidental findings may help the diagnosis. The hormonal evaluation of pituitary adenomas is different from the algorithm used in the disorders of peripheral endocrine organs. The first-line therapy of prolactinomas are the dopamine agonists, and the aims of the treatment are to normalize the prolactin level, restore fertility in child-bearing age, decrease tumor mass, save or improve the residual pituitary function and inhibit the relapse of the disease. The available dopamine agonists in Hungary are bromocriptine and quinagolide. In case of tumors with good therapeutic response, medical therapy can be withdrawn after 3-5 years; hyperprolactinemia will not recur in 2/3 of these patients. Neurosurgery is the primary therapy of GH-, ACTH-, TSH-producing and inactive adenomas. In the last decades, significant improvement has been reached in surgical procedures, resulting in low mortality rates. Acromegalic patients with unresectable tumors have a great benefit from somatostatin analog treatment. The growth hormone receptor antagonist pegvisomant is the newest modality for the treatment of acromegaly. The medical therapy of Cushing's disease is still based on the inhibition of steroid production. A new, promising somatostatin analog, pasireotide is evaluated in clinical trials. The rare TSH-producing tumor can respond to both dopamine agonist and somatostatin analog therapy. The application of conventional radiotherapy has decreased; radiotherapy is mainly used in the treatment of invasive, incurable or malignant tumors. Further studies are needed to elucidate the exact role of radiosurgery and fractionated stereotaxic irradiation in the treatment of pituitary tumors.

Hyperprolactinaemia

Hyperprolactinaemia is a common condition with varied aetiology. It is more frequent in women, but also seen in men and even in adolescence and childhood. Prolactin is mainly a lactogenic hormone but has other actions. Most cases present with amenorrhoea and infertility and are managed by gynaecologists. However, multidisciplinary involvement may be required in some cases. Evidence relating to aetiology, clinical features, pathogenesis and management has been discussed.

Recurrence of hyperprolactinemia after withdrawal of long-term cabergoline therapy

CONTEXT

Recurrence of hyperprolactinemia after cabergoline withdrawal ranges widely from 36 to 80%. The Pituitary Society recommends withdrawal of cabergoline in selected patients.

OBJECTIVE

Our aim was to evaluate recurrence of hyperprolactinemia in patients meeting The Pituitary Society guidelines.

DESIGN

Patients were followed from the date of discontinuation to either relapse of hyperprolactinemia or the day of last prolactin test.

SETTING

We conducted the study at an academic medical center.

PATIENTS

Forty-six patients meeting Pituitary Society criteria (normoprolactinemic and with tumor volume reduction after 2 or more years of treatment) participated in the study.

INTERVENTIONS

After withdrawal, if prolactin returned above reference range, another measurement was obtained within 1 month, symptoms were assessed by questionnaire, and magnetic resonance imaging was performed.

MAIN OUTCOME MEASURES

We measured risk of and time to recurrence estimates as well as clinical predictors of recurrence.

RESULTS

Mean age of patients was 50 +/- 13 yr, and 70% were women. Thirty-one patients had microprolactinomas, 11 had macroprolactinomas, and four had nontumoral hyperprolactinemia. The overall recurrence was 54%, and the estimated risk of recurrence by 18 months was 63%. The median time to recurrence was 3 months (range, 1-18 months), with 91% of recurrences occurring within 1 yr after discontinuation. Size of tumor remnant prior to withdrawal predicted recurrence [18% increase in risk for each millimeter (95% confidence interval, 3-35; P = 0.017)]. None of the tumors enlarged in the patients experiencing recurrence, and 28% had symptoms of hypogonadism.

CONCLUSIONS

Cabergoline withdrawal is practical and safe in a subset of patients as defined by The Pituitary Society guidelines; however, the average risk of long-term recurrence in our study was over 60%. Close follow-up remains important, especially within the first year.

Long-term control of macroprolactinomas

Hyperprolactinemia is the most prevalent hypothalamic-pituitary dysfunction, with prolactinomas being its main cause. Microprolactinomas (diameter < 10 mm) represent approximately 60% of the prolactin-secreting adenomas, and are far more common in women than in men, whereas macroadenomas have roughly the same prevalence in both genders. The treatment of patients harboring macroprolactinomas is highly gratifying, with more than 80% of them adequately controlled by dopamine-agonist (DA) drugs: cabergoline being the most efficacious to date. Emerging evidence points to remission of the disease after long-term DA therapy in a significant number of patients. The remaining cases, mainly those with enclosed tumors, may be treated successfully by pituitary surgery. Radiotherapy is reserved for cases with dopaminergic drug resistance not surgically cured. The development of new therapeutic approaches may turn the control of the subset of macroprolactinomas refractory to both DA and surgery into reality.

Hyperprolactinaemia

Hyperprolactinaemia is a frequent cause of reproductive problems encountered in clinical practice. A variety of pathophysiological conditions can lead to hyperprolactinaemia; therefore, pregnancy, drug effects, hypothyroidism and polycystic ovary syndrome should be excluded before investigating for prolactin-secreting pituitary tumours. Prolactinomas are mainly diagnosed in women aged 20-40 years. They present with clinical features of hyperprolactinaemia (galactorrhoea, gonadal dysfunction), and more rarely with large tumours, headache and visual field loss due to optic chiasm compression. Medical therapy with dopamine agonists is the treatment of choice for both micro- and macroprolactinomas. Tumour shrinkage and restoration of gonadal function are achieved in the majority of cases with dopamine agonists. A trial of withdrawal of medical therapy may be considered in many patients with close follow-up. Pituitary surgery and radiotherapy currently have very limited indications. Pregnancies in patients with prolactinomas need careful planning and close monitoring.

Hyperprolactinemia and prolactinomas

Any process interfering with dopamine synthesis, its transport to the pituitary gland, or its action at the level of lactotroph dopamine receptors can cause hyperprolactinemia. As described in this article, considering the complexity of prolactin regulation, many factors could cause hyperprolactinemia, and hyperprolactinemia can have clinical effects not only on the reproductive axis. Once any drug effects are excluded, prolactinomas are the most common cause of hyperprolactinemia. The most frequent symptom is hypogonadism in both genders. Medical and surgical therapies generally have excellent results, and most prolactinomas are well controlled or even cured in some cases.

Prolactin levels and examination with breast ultrasound or mammography

OBJECTIVE

Stresses including surgery, exercise, nipple stimulation, and chest wall injury such as mechanical trauma, burns, surgery, herpes zoster of thoracic dermatomes, hypoglycaemia and acute myocardial infarction cause significant elevation of prolactin levels. The aim of the present study was to evaluate the changes in prolactin level during mammography and ultrasonographic examination.

MATERIALS AND METHODS

Seventy-four premenopausal (mean age, 32.1+/-7.3 y) and 81 post-menopausal women (mean age, 48.3+/-8.9 y) were enrolled into the study. Premenopausal women were evaluated with ultrasound (Senographe 600 T [General Electric]) and post-menopausal women were examined with mammography (Mammomat 3000 [Siemens]). Blood samples for prolactin were taken prior to ultrasound or mammography and 15, 30 and 45 min after ultrasound or mammography.

RESULTS

Mean baseline serum prolactin level was 7.2+/-0.9 ng/ml in premenopausal women before ultrasound. Mean baseline serum prolactin level was 5.4+/-0.4 ng/ml in post-menopausal women before mammography. It was found that there were no significant changes in prolactin levels after ultrasound or mammography (P > 0.05). Mean levels of baseline prolactin were statistically significant higher in premenopausal than in post-menopausal women (P = 0.03).

CONCLUSION

Mammography and ultrasonographic examination have no acute effect on serum prolactin levels in either group. There is no need to wait before measuring the prolactin level after mammographic or ultrasonographic breast examination.

Hyperprolactinemia

In several respects prolactin is unique among anterior pituitary hormones. The primary regulation of prolactin secretion is mediated through hypothalamic inhibition, and the diagnosis of hyperprolactinemia can be established without the use of stimulation or suppression tests. Documenting the presence of hyperprolactinemia is not difficult-the challenge is in identifying the cause of the hormone hypersecretion. With immunoradiometric assays falsely low levels of prolactin are occasionally seen in patients with macroadenomas and very high serum prolactin (the hook effect). Macroprolactin should be suspected when a patient with hyperprolactinemia does not present with typical clinical symptoms, and all hyperprolactinemic sera should be screened for macroprolactin. With prolactinomas, prolactin levels generally parallel tumor size. Prolactin secreting macroadenomas are typically associated with levels that exceed 250 microg/l and may exceed 1,000 microg/l. Large non-functioning adenomas also lead to hyperprolactinemia but levels virtually never exceed 94 microg/l. Acquired and isolated prolactin deficiency is rare.

Predictors of remission of hyperprolactinaemia after long-term withdrawal of cabergoline therapy

BACKGROUND

Remission rates of 76, 69.5 and 64.3% have been reported in patients with nontumoural hyperprolactinaemia (NTH), microprolactinoma and macroprolactinoma, respectively, 2-5 years after cabergoline (CAB) withdrawal.

OBJECTIVE

To report the estimated recurrence rate at 24-96 months after CAB withdrawal and indicate predictors of disease remission.

DESIGN

Observational, analytical, prospective.

PATIENTS

Of 381 previously untreated de novo patients with hyperprolactinaemia, 221 (58%) (173 women, 48 men; 27 with NTH, 115 with micro-, and 79 with macroprolactinoma) were studied.

MEASUREMENTS

Using multiple regression analysis the diagnostic accuracy of nadir PRL levels (t = 7.6, P < 0.0001) and nadir maximal tumour diameter at CAB withdrawal (t = 3.9, P < 0.001) was analysed using receiver operating characteristic (ROC) curves.

RESULTS

The recurrence of hyperprolactinaemia was 25.9, 33.9 and 53.1% in patients with NTH, micro- or macroprolactinoma, respectively. To predict the last PRL level after withdrawal, the optimum cut-off of nadir PRL levels at withdrawal was 162 mU/l (5.4 microg/l) [sensitivity (95% CI) 76% (67-84%), specificity 65% (51-77%)] and that of nadir maximal tumour diameter was 3.1 mm [sensitivity 52% (41-63%), specificity 86% (79-91%)]. The patients achieving both nadir PRL levels </= 162 mU/l and maximal tumour diameter </= 3.1 mm (n = 111) at CAB withdrawal had a significantly lower Kaplan-Meier estimate of recurrence of hyperprolactinaemia (20%) at 24-96 months than those who did not fulfil any of these criteria [(n = 38) 90%; P < 0.0001]. Patients achieving nadir PRL levels </= 162 mU/l (n = 26) or maximal tumour diameter </= 3.1 mm during CAB treatment (n = 46) had an estimated recurrence rate of hyperprolactinaemia of 50 and 56%, respectively.

CONCLUSION

Persistent remission of hyperprolactinaemia without any evidence of tumour re-growth after 24-96 months of CAB withdrawal occurred in the majority of patients with NTH and microprolactinoma and in about half of those with macroprolactinoma. Nadir PRL levels and maximal tumour diameter at CAB withdrawal of </= 162 mU/l and </= 3.1 mm predicted remission of hyperprolactinaemia in 80% of patients.

Long-term management of prolactinomas

Prolactinomas are a frequent cause of gonadal dysfunction and infertility, especially in young women. The regulation of prolactin secretion and the efficacy of dopamine agonists in the therapy of prolactinomas are well established. The current challenges in management of prolactinomas are related to follow-up after successful therapy. Issues and questions to be addressed in this approach to long-term management of prolactinomas include the frequency of radiographic monitoring, effect of pregnancy and menopause, safety of estrogen in women taking oral contraceptives, and the potential for discontinuation of dopamine agonist therapy.

Drug treatment of hyperprolactinemia

Medical treatment of hyperprolactinemia is based upon use of dopamine agonists (DA): bromocriptine, lisuride, quinagolide and cabergoline. In over 80% of cases, these drugs induce normal prolactinemia and ovulatory cycles. In resistant cases, the DA should be changed. Tolerance may occasionally be poor, particularly with bromocriptine, which appears less well-tolerated than quinagolide and than cabergoline above all. In the event of intolerance to a given DA, another should be tried. In patients with macroprolactinoma treated with DA, MRI monitoring should be carried out after 3 months of treatment to verify tumor size reduction, then after 1 year, yearly for the next 5 years and once every 5 years if adenoma size is stable. In cases of microprolactinoma, control under treatment is pointless. MRI may be performed after 1 year and then after 5 years. Once normal prolactin levels have been achieved, attempts may be made to stop the treatment. When a prolonged treatment is interrupted, especially with cabergoline, progressive increase in serum prolactin and return of hyperprolactinemia symptoms are seen in only around 20-30% of cases, particularly when residual adenoma exists after prolonged treatment. Nevertheless, prolactin levels should continue to be monitored after discontinuation of DA, possibly with MRI monitoring, since prolactin levels may rise again after a number of months or years. When normal prolactin levels have been achieved with DA, another solution consists in reducing the dose or dosing frequency of DA in steps to the lowest effective dose consistent with maintenance of normal prolactin levels and stable adenoma size. For drug-induced hyperprolactinemia, where the causative medication cannot be withdrawn, it is often pointless and possibly even dangerous to administer a DA. It is therefore necessary to check for absence of pituitary adenoma and where necessary, begin treatment with sex steroids so as to ensure satisfactory impregnation with sex steroids and avoid osteoporosis. For macroprolactinoma, the first-line treatment is drug therapy with DA. At present, there is no evidence to suggest that prior treatment with DA can modify the outcome of surgery. With microprolactinoma, DA treatment offers a good first-line therapeutic option but surgery may also be useful. DAs for microprolactinoma may be withdrawn after menopause.

Temozolomide in the treatment of an invasive prolactinoma resistant to dopamine agonists

Prolactinomas are common tumors of the anterior pituitary gland. While conventional therapies, including dopamine agonists, transsphenoidal surgery and radiotherapy, are usually effective in controlling tumor growth, some patients develop treatment-resistant tumors. In this report, we describe a patient with an invasive prolactinoma resistant to conventional therapy that responded to the administration of the alkylating agent, temozolomide.

Prolactin Levels in Workers Exposed to Chemical, Physical and Psycho‐Social Urban Stressors

The aim of this study was to evaluate whether traffic police officers exposed to chemical, physical and psycho-social stressors, are at risk for alterations in plasma levels of prolactin (PRL) compared to a control group. Plasma PRL levels were evaluated in 92 male and 51 female, non-smoker, traffic police officers exposed to urban stressors and in 92 male and 51 female controls, matched by sex, age and working life (mean, SD and distribution), after excluding workers with the principal extra-occupational confounding factors. Mean PRL levels were significantly higher than controls in non-smoker, male and female traffic police officers (respectively, p=0.000 and p=0.013). The number of non-smoker, male and female traffic police officers with PRL values outside the upper normal limit for our laboratory was higher than, but not significantly different from controls. Mean PRL levels were not significantly higher than controls in smoker, male and female traffic police officers. The number of smoker, male and female traffic police officers with PRL values outside the normal limit for our laboratory was not significantly different from controls. The results suggest that exposure to urban chemical and physical stressors, interacting with psychosocial factors, may have an influence on PRL levels in traffic police officers. The level of plasma PRL might be a useful early biological marker for workers exposed to urban stressors.

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future.

Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas

In June 2005, an ad hoc Expert Committee formed by the Pituitary Society convened during the 9th International Pituitary Congress in San Diego, California. Members of this committee consisted of invited international experts in the field, and included endocrinologists and neurosurgeons with recognized expertise in the management of prolactinomas. Discussions were held that included all interested participants to the Congress and resulted in formulation of these guidelines, which represent the current recommendations on the diagnosis and management of prolactinomas based upon comprehensive analysis and synthesis of all available data.