Is surgery a first-line treatment for prolactinomas (prolactin-secreting pituitary tumors)?

From the Guidelines

Surgery is not recommended as the first-line treatment for prolactinomas. The standard first-line treatment is dopamine agonist medication, typically cabergoline, as it has been shown to be effective in reducing serum prolactin concentrations and inducing tumor shrinkage, with a superior effectiveness and lower adverse effect profile compared to other dopamine agonists 1.

Key Considerations

• Dopamine agonist medication, such as cabergoline, is the preferred initial treatment due to its high efficacy in reducing prolactin levels and shrinking tumor size in approximately 80-90% of patients.
• Surgery is generally reserved for specific situations, including:
  • Intolerance or resistance to medical therapy 1.
  • Rapid visual loss requiring immediate decompression.
  • Pregnancy with symptomatic tumor growth.
  • Patient preference for surgical intervention after understanding the alternatives.
• The preference for medical therapy over surgery is based on the high efficacy of dopamine agonists, their non-invasive nature, and the relatively high recurrence rates (20-50%) following surgical resection of prolactinomas.
• Surgery carries risks of hypopituitarism, diabetes insipidus, and other surgical complications, emphasizing the need for careful patient selection and monitoring.

Monitoring and Adjustments

• Patients should be monitored with prolactin levels, visual field testing, and MRI imaging to assess treatment response.
• Medication adjustments should be made accordingly to ensure optimal treatment outcomes.
• In cases where surgery is indicated, transsphenoidal surgery is the technique of choice, even in patients with incompletely pneumatized sphenoid sinuses, and endoscopic rather than microscopic transsphenoidal surgery may be considered for its potentially superior efficacy in preserving pituitary function 1.

From the Research

Surgery as First-Line Treatment for Prolactinomas

• Surgery is being considered as a first-line treatment option for prolactinomas, with studies showing its safety and effectiveness 2, 3.
• A study published in 2021 found that surgery exhibited better outcomes in terms of dopamine agonist (DA)-free remission and structural response, compared to DA treatment 2.
• Another study published in 2022 proposed a 'surgery-first' approach for a subset of prolactinomas, suggesting that transsphenoidal surgery should be considered as a first-line treatment option for both micro- and macro-prolactinomas 3.
• However, surgery is not without risks, and the decision to use it as a first-line treatment should be made on an individual basis, taking into account the patient's specific circumstances and the availability of skilled and experienced pituitary surgeons 2, 3.

Comparison with Medical Treatment

• Medical treatment with dopamine agonists has long been the recommended first-line treatment for prolactinomas, but surgery is gaining recognition as a viable alternative 4, 5.
• A study published in 2018 compared the treatment outcomes of medical versus surgical treatment for prolactinomas, finding that both modalities can offer excellent outcomes, but with different risks and benefits 6.
• The study suggested that 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 when combined with continued postoperative medical therapy 6.

Patient Selection and Outcomes

• Patient selection is crucial when considering surgery as a first-line treatment for prolactinomas, with factors such as tumor size, invasiveness, and patient preferences influencing the decision 2, 3.
• A study published in 2023 analyzed the outcome of surgical resection of prolactinomas, finding a high remission rate and low complication rate, but also highlighting the importance of individualized treatment decisions 5.
• The study found that 63.3% of patients achieved endocrine remission, with a mean follow-up of 34.9 months, and that the consistently good results of transsphenoidal surgery have led to a greater acceptance of surgery in the treatment of prolactinomas in recent years 5.