From the Guidelines
Monitoring of prolactinomas requires a comprehensive approach, including regular assessment of serum prolactin levels, tumor size, and clinical symptoms, with the goal of minimizing morbidity, mortality, and improving quality of life. Patients should have prolactin levels measured every 3 months initially after diagnosis or treatment initiation, then every 6-12 months once stable 1.
Key Monitoring Components
- MRI imaging should be performed 3-6 months after starting dopamine agonist therapy, such as cabergoline 0.25-1 mg twice weekly, then annually until tumor stabilization, after which imaging frequency can decrease to every 2-3 years 1.
- Visual field testing is necessary for macroadenomas near the optic chiasm, initially and whenever symptoms change.
- Clinical assessment should include evaluation of symptoms like galactorrhea, menstrual irregularities, erectile dysfunction, and medication side effects.
Medication Management
- For patients with normalized prolactin levels and significant tumor shrinkage, a trial of medication withdrawal may be considered after 2-3 years of stable treatment, though recurrence risk is 50-80% 1.
- During pregnancy, clinical monitoring is preferred over biochemical testing as prolactin naturally increases.
Additional Considerations
- An echocardiogram should be offered at the start of treatment with a dopamine agonist, with yearly surveillance echocardiography for patients receiving >2 mg per week cabergoline and every 5 years if on ≤2 mg per week 1.
- Assessment of bone mineral density (BMD) 2 years after diagnosis might be important in patients with prolactinoma, considering the potential impact of delayed growth and puberty on peak bone mineral accrual 1.
Treatment Recommendations
- Cabergoline is the dopamine agonist of choice given its superior effectiveness and lower adverse effect profile 1.
- The use of cabergoline and treatment for more than 2 years were associated with a decreased relapse rate, and tapering doses prior to withdrawal reduced the risk of relapse 1.
From the Research
Monitoring of Prolactinoma
- The monitoring of prolactinoma involves regular check-ups and tests to ensure the tumor is not growing or causing any problems 2.
- A study published in the European Journal of Endocrinology in 2017 found that MRI follow-up is unnecessary in patients with macroprolactinomas and long-term normal prolactin levels on dopamine agonist treatment 2.
- The study included 115 patients with macroprolactinomas who were treated with dopamine agonists and had regular follow-up with pituitary MRI and prolactin levels for at least 48 months 2.
- The results showed that no significant increase in tumor volume was observed during the follow-up period, and MRI follow-up appeared unnecessary in patients with biologically controlled macroprolactinomas 2.
Treatment and Management
- Dopamine agonists, such as cabergoline, are the first-line treatment for prolactinomas 3, 4, 5.
- A study published in the Endocrine journal in 2018 found that the addition of octreotide LAR to ongoing cabergoline treatment may be effective in some patients with dopamine agonist-resistant macroprolactinomas 3.
- Another study published in the Cureus journal in 2022 found that cabergoline is superior to bromocriptine in prolactin normalization and tumor shrinkage 4.
- For patients with prolactinomas resistant to dopamine agonists, other treatment options include temozolomide, aromatase inhibitors, pasireotide, peptide receptor radionuclide therapy, immune-checkpoint inhibitors, tyrosine-kinase inhibitors, and everolimus 5.
Resistance to Dopamine Agonists
- Some patients with prolactinomas may develop resistance to dopamine agonists, which can make treatment more challenging 3, 5, 6.
- A study published in the Pituitary journal in 2011 found that the combined treatment with cabergoline and octreotide may be a good therapeutic course of action for select cases of invasive dopamine-resistant macroprolactinomas 6.
- The expression and functionality of somatostatin receptors should be investigated in these tumors, as it may help guide treatment decisions 6.