Long-term management of prolactinomas--use of long-acting dopamine agonists

Broad clinical spectrum and diverse outcomes of prolactinoma with pediatric onset: medication-resistant and recurrent cases

Prolactinoma is a benign tumor of the pituitary gland that rarely occurs in children and adolescents; thus, the clinical spectrum and long-term prognosis in these patients remain unknown. This study was performed to investigate the long-term outcomes of medical treatment and the prognostic factors for remission and relapse in children and adolescents with prolactinoma. Three male subjects and four female subjects between the ages of 7- and 17-years-old were included in this study. The mean initial serum prolactin level was 443 ± 251.8 ng/mL (range, 152-946 ng/mL). During the follow-up period (range, 0.6-20 years), a dopamine agonist was administered, and surgery or radiotherapy was performed in cases of resistance to medical treatment or relapse. Unlike female subjects with macroadenoma who often exhibit a good clinical course, two male subjects with early onset macroadenoma presented with visual disturbances. These subjects showed resistance to medical therapy and relapsed, eventually requiring surgical removal and radiotherapy; one of the subjects manifested a metastatic thrombus in the internal jugular vein. In conclusion, pediatric prolactinoma exhibits a broad clinical spectrum, a relatively high incidence of macroadenoma, resistance to medical therapy, and frequent tumor relapses. In addition, a poor prognosis appears to be correlated with male sex, age at disease onset, and histopathological characteristics.

Medical versus surgical treatment of prolactinomas: an analysis of treatment outcomes

INTRODUCTION

Prolactinomas are unique tumors that may go into both hormonal and radiographic remission with dopamine agonist therapy or transsphenoidal surgery. Regardless of modality, the goals of therapy remain the same: (1) biochemical remission, including reduction of prolactin and normalization of sex hormones; (2) radiographic tumor control, with a range including prevention of tumor growth, tumor regression, or complete tumor resolution; (3) resolution of preoperative symptoms, including those that are hormonal or neurologic; and (4) prevention of new hypopituitarism or new neurologic symptoms.

AREAS COVERED

In the following review, we performed a search of the literature using keywords 'prolactinoma,' 'dopamine agonist,' 'surgery,' 'cost-effectiveness,' 'recurrence,' and 'complication' to compare the relative merits of medical versus surgical therapy for prolactinoma, including special circumstances such as cystic tumors, pregnant patients, and the cost-effectiveness of different strategies.

EXPERT COMMENTARY

Medical therapy can offer a cure, but surgery provides an important adjunct to patients with resistance or intolerance to dopamine agonists, and offers excellent outcomes including when combined with continued postoperative medical therapy. Further head to head comparisons will benefit patients and practitioners weighing the relative risks and benefits of medical and surgical intervention, including the issue of their relative cost-effectiveness.

Update on prolactinomas. Part 2: Treatment and management strategies

The authors present an update on the various treatment modalities and discuss management strategies for prolactinomas. Prolactinomas are the most common type of functional pituitary tumor. Effective hyperprolactinemia treatment is of great importance, due to its potential deleterious effects including infertility, gonadal dysfunction and osteoporosis. Dopamine agonist therapy is the first line of treatment for prolactinomas because of its effectiveness in normalizing serum prolactin levels and shrinking tumor size. Though withdrawal of dopamine agonist treatment is safe and may be implemented following certain recommendations, recurrence of disease after cessation of the drug occurs in a substantial proportion of patients. Concerns regarding the safety of dopamine agonists have been raised, but its safety profile remains high, allowing its use during pregnancy. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or are experiencing progressive tumor growth. Surgical resection can also be considered as a primary treatment for those with smaller focal tumors where a biochemical cure can be expected as an alternative to lifelong dopamine agonist treatment. Stereotactic radiosurgery also serves as an option for those refractory to medical and surgical therapy.

[Treatment of pituitary gland hyperfunction: from acromegaly to prolactinoma]

Evidence based drug therapy is currently available for the treatment of prolactinomas and growth hormone secreting adenomas (acromegaly). Dopamine agonists such as bromocriptine, quinagolide or cabergoline represent the standard therapy for the treatment of micro- and macro-prolaktinomas. In pregnancy, more differentiated, individual and patient-adapted therapeutic procedures have to be considered. Transsphenoidal adenomectomy is the treatment of choice for patients suffering from acromegaly. If biochemical cure (defined by normalized IGF-1 serum levels or by a GH nadir <1 microg/l during a 3-h oral glucose tolerance test) cannot be achieved, somatostatin analogues such as octreotide and lanreotide are effective. In some cases, dopamine agonists can be added. In therapy-resistant cases, growth hormone receptor antagonists can be used.