Approach to the Patient With Prolactinoma Auriemma, Renata S; Pirchio, Rosa; Pivonello, Claudia ...
The journal of clinical endocrinology and metabolism,
08/2023, Letnik:
108, Številka:
9
Journal Article
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Abstract
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.
Somatostatin analogues (SA) currently represent the medical treatment option for most patients with acromegaly and neuroendocrine tumors. In the setting of acromegaly, SA are indicated both as ...first-line treatment and as adjuvant treatment after unsuccessful surgery. Resistance to SA is still not fully defined but is generally considered to occur in the patients without control of GH and IGF-I excess with high dosages of the drugs. Tumor shrinkage is also a relevant clinical outcome of SA treatment. This review examines the current state of our understanding of these treatments and provides a definition of SA resistance.
Somatostatin analogs (SA) are widely used in acromegaly, either as first-line or adjuvant treatment after surgery. First-line treatment with these drugs is generally used in the patients with macroadenomas or in those with clinical conditions so severe as to prevent unsafe reactions during anesthesia. Generally, the response to SA takes into account both control of GH and IGF-I excess, with consequent improvement of clinical symptoms directly related to GH and IGF-I excess, and tumor shrinkage. This latter effect is more prominent in the patients treated first-line and bearing large macroadenomas, but it is also observed in patients with microadenomas, even with little clinical implication. Predictors of response are patients' gender, age, initial GH and IGF-I levels, and tumor mass, as well as adequate expression of somatostatin receptor types 2 and 5, those with the highest affinity for octreotide and lanreotide. Only sporadic cases of somatostatin receptor gene mutation or impaired signaling pathways have been described in GH-secreting tumors so far. The response to SA also depends on treatment duration and dosage of the drug used, so that a definition of resistance based on short-term treatments using low doses of long-acting SA is limited. Current data suggest that response to these drugs is better analyzed taking together biochemical and tumoral effects because only the absence of both responses might be considered as a poor response or resistance. This latter evidence seems to occur in 25% of treated patients after 12 months of currently available long-acting SA.
Introduction
In nearly all cases, acromegaly is caused by excess GH from a pituitary adenoma, resulting in elevated circulating levels of GH and, subsequently, IGF-1. Treatment goals are to eliminate ...morbidity and restore the increased mortality to normal rates. Therapeutic strategies aim to minimize tumor mass and normalize GH and IGF-1 levels. Somatostatin analogues are the medical treatment of choice in acromegaly, as first-line or post-surgical therapy, and have proven efficacy in pituitary tumor volume reduction (TVR).
Methods
Here we review the effects of somatostatin analogue therapy on pituitary tumor volume in patients with acromegaly.
Results
TVR with somatostatin analogues may be mediated by direct anti-proliferative effects via activation of somatostatin receptors, or by indirect effects, such as angiogenesis inhibition, and is more pronounced when they are administered as first-line therapy. Various studies of first-line treatment with octreotide LAR have shown significant TVR in ≥73 % of patients. First-line treatment with lanreotide Autogel has shown evidence of TVR, although more studies are needed. In a recent randomized, double-blind, 12-month trial in 358 medical-treatment-naïve acromegaly patients, significant TVR was achieved by 81 % of patients administered pasireotide LAR and 77 % administered octreotide LAR. Pre-operative somatostatin analogue therapy may also induce TVR and improve post-operative disease control compared with surgery alone. TVR is progressive with prolonged treatment, and decreased IGF-1 levels may be its best predictor, followed by age and degree of GH decrease. However, TVR does not always correlate with degree of biochemical control.
Conclusion
Somatostatin analogues (first- or second-line treatment) are the mainstay of medical therapy and, as first-line medical therapy, are associated with significant pituitary TVR in most patients.
Metabolic effects of prolactin Pirchio, Rosa; Graziadio, Chiara; Colao, Annamaria ...
Frontiers in endocrinology (Lausanne),
09/2022, Letnik:
13
Journal Article
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Over the last years, the metabolic role of PRL has emerged. PRL excess is known to promote weight gain, obesity, metabolic syndrome, and impairment in gluco-insulinemic and lipid profiles, likely due ...to the suppression of physiologic dopaminergic tone. Prolactin receptors and dopamine receptors type 2 have been demonstrated to be expressed on both human pancreatic β- cell and adipocytes, supporting a key role of prolactin and dopamine in peripheral metabolic regulation. Medical treatment with the dopamine agonists bromocriptine and cabergoline has been demonstrated to decrease the prevalence of metabolic syndrome and obesity, and significantly improve gluco-insulinemic and lipid profiles. In hyperprolactinemic men with concomitant hypogonadism, correction of hyperprolactinaemia and testosterone replacement has been proven to restore metabolic impairment. In turn, low prolactin levels have also been demonstrated to exert a detrimental effect on weight gain, glucose and lipid metabolism, thus leading to an increased prevalence of metabolic syndrome. Therefore, PRL values ranging from 25 to 100 mg/L, in absence of other recognizable pathological causes, have been proposed to represent a physiological response to the request for an increase in metabolic activity, and nowadays classify the so-called HomeoFIT- PRL as a promoter of metabolic homeostasis. The current review focuses mainly on the effects of hyperprolactinemia and its control by medical treatment with DAs on the modulation of food intake, body weight, gluco-insulinemic and lipid profile. Furthermore, it provides the latest knowledge about the metabolic impact of hypoprolactinemia.
Dopamine Agonists: From the 1970s to Today Auriemma, Renata S; Pirchio, Rosa; De Alcubierre, Dario ...
Neuroendocrinology,
07/2019, Letnik:
109, Številka:
1
Journal Article
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The discovery of dopamine inhibitory effects on prolactin secretion has led to an era of successful dopaminergic therapy for prolactinomas. Herein we provide an overview of the evolution of dopamine ...agonists and their use in patients with PRL-secreting pituitary tumors, starting from the 1970s up to today, highlighting that normalization of PRL levels, restoration of eugonadism, and reduction of tumor mass can be achieved in the majority of patients by treatment with dopamine agonists.
Acromegaly is associated with an enhanced mortality, with cardiovascular and respiratory complications representing not only the most frequent comorbidities but also two of the main causes of deaths, ...whereas a minor role is played by metabolic complications, and particularly diabetes mellitus. The most prevalent cardiovascular complications of acromegaly include a cardiomyopathy, characterized by cardiac hypertrophy and diastolic and systolic dysfunction together with arterial hypertension, cardiac rhythm disorders and valve diseases, as well as vascular endothelial dysfunction. Biochemical control of acromegaly significantly improves cardiovascular disease, albeit completely recovering to normal mainly in young patients with short disease duration. Respiratory complications, represented mainly by sleep-breathing disorders, particularly sleep apnea, and respiratory insufficiency, frequently occur at the early stage of the disease and, although their severity decreases with disease control, this improvement does not often change the indication for a specific therapy directed to improve respiratory function. Metabolic complications, including glucose and lipid disorders, are variably reported in acromegaly. Treatments of acromegaly may influence glucose metabolism, and the presence of diabetes mellitus in acromegaly may affect the choice of treatments, so that glucose homeostasis is worth being monitored during the entire course of the disease. Early diagnosis and prompt treatment of acromegaly, aimed at obtaining a strict control of hormone excess, are the best strategy to limit the development or reverse the complications and prevent the premature mortality.
Prolactin (PRL) is a crucial mediator of gluco-insulinemic metabolism.
Dissecting glucose metabolism during and after pregnancy in patients with prolactinomas.
52 patients treated with cabergoline ...(CAB) were evaluated before conception, during pregnancy and up to 10 years after delivery. During pregnancy, CAB was discontinued, while it was restarted in 57.7 % of patients after delivery, due to recurrent hyperprolactinemia (RH). Hormonal (serum PRL) and metabolic (HbA1c, fasting glucose/FG, glucose tolerance) parameters were assessed.
During pregnancy, PRL gradually increased, while FG remained stable. An inverse correlation between PRL and FG was found in the first (p=0.032) and third (p=0.048) trimester. PRL percent increase across pregnancy was inversely correlated with third trimester FG. Serum PRL before conception emerged as predictive biomarker of third trimester FG (τ=2.603; p=0.048). Elderly patients with lower HbA1c at first trimester and lower FG at 3 years postpartum, delivered infants with reduced birth weight. Breastfeeding up to 6 months correlated with lower FG at 4 and 10 years postpartum. A positive correlation between BMI and FG at 10 years after delivery (p=0.03) was observed, particularly in overweight/obese patients requiring higher CAB doses. Patients with RH who had to restart CAB showed shorter breastfeeding duration and higher FG at 2 years postpartum.
Low PRL levels before pregnancy may be detrimental to FG during pregnancy. CAB duration and dose may influence long-term glucose tolerance, besides family history and BMI. Pre-conceptional metabolic management should be recommended to reduce the risk of gestational and type 2 diabetes mellitus.
The pathogenesis of obesity and alterations in glucose profile have been linked to PRL excess, as it is reportedly associated with metabolic syndrome in thereabout one third of patients.
exposure of ...pancreatic islet to PRL is known to stimulate insulin secretion and β-cell proliferation, and in turn overexpression of PRL in β-cells increases insulin release and β-cell replication. PRL excess has been found to worsen glucose profile because it reduces glucose tolerance and induces insulin resistance either in obese and non-obese patients. To note, pancreatic β-cells and adipocytes widely express dopamine receptors type 2, and dopamine has been hypothesized to play a key role as modulator of insulin and adipose functions. The dopamine agonists bromocriptine and cabergoline significantly improve abnormalities in glucose profile and reduce the prevalence of metabolic syndrome in a remarkable proportion of patients, regardless of whether body weight and PRL status may change. However, in men with hyperprolactinemia complicated by hypogonadism, testosterone replacement can ameliorate insulin resistance and abnormalities in glucose metabolism. Therefore, in patients with PRL-secreting pituitary adenomas control of PRL excess by dopamine agonists is mandatory to improve glucose and insulin abnormalities.
•Most prolactinomas are diagnosed in women of reproductive age and are generally microadenomas. Prolactinomas diagnosed in postmenopausal women are less common and usually not associated to the ...typical syndrome induced by prolactin excess, including infertility and oligo-amenorrhea.•The diagnosis of prolactinomas after menopause generally results in a clinically relevant delay.•Data on the management and prognosis of prolactinomas in postmenopausal women are scant and prospective studies are completely lacking.•The physiologic decline of prolactin levels during menopause and the lack of a clinical syndrome characterized by fertility concerns impose the need for a careful reassessment of therapeutic management in such patients.•Postmenopausal women with microprolactinomas may be successfully withdrawn from medical therapy with dopamine agonists, whereas those with macroprolactinomas should be maintained on dopamine agonists to prevent potential, although rare, tumor enlargement.
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.
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