Can prolactinomas go away with treatment?

Treatment and Resolution of Prolactinomas

Prolactinomas can go away with treatment, with dopamine agonists normalizing prolactin levels in 60-70% of patients and achieving tumor shrinkage in 80-88% of cases. 1

First-Line Treatment: Dopamine Agonists

• Cabergoline is the dopamine agonist of choice due to its superior effectiveness and better side effect profile compared to other options 1, 2
• Cabergoline normalizes prolactin in 60-70% of patients and reduces tumor size by 80-88% 1
• Standard initial dosing starts at 0.25 mg twice weekly, with gradual increases up to 2 mg/week for most patients 2, 3
• Smaller prolactinomas (<13.5 mm) typically achieve normalization of prolactin levels with conventional cabergoline doses (up to 2 mg/week) 1
• Larger tumors (>20 mm) may require surgery in addition to medication 1

Treatment Response and Remission

• After achieving normal prolactin levels for at least 2 years and no visible tumor on MRI, gradual cabergoline dose reduction can be attempted 1
• Complete remission with medication discontinuation is possible, but relapse rates vary (26-89%) 1
• Younger patients and those with high initial prolactin levels (indicating larger tumors) are less likely to achieve complete remission 1
• Tapering doses prior to withdrawal reduces the risk of relapse 1

Management of Resistant Cases

• For patients resistant to standard doses, graduated dose increments up to 3.5 mg/week can be offered 1
• In exceptional cases, doses up to 7 mg/week may be considered 1
• Dopamine agonist resistance is defined as failure to achieve normal prolactin levels and/or less than 50% tumor size reduction after 3-6 months of maximally tolerated doses 1
• Resistance occurs in approximately 10% of patients treated with cabergoline 4

Second-Line Options for Resistant Cases

• Surgery should be considered when:
  • The patient is unable to tolerate or is resistant to high-dose cabergoline 1
  • The patient develops deteriorating vision on cabergoline 1
• Radiotherapy may be considered if surgery is not an option 1
• Temozolomide, a DNA alkylating agent, has shown effectiveness in 40-50% of resistant cases 5

Monitoring During Treatment

• For macroprolactinomas, MRI should be repeated 3-6 months after starting cabergoline 1
• For microprolactinomas, re-imaging depends on clinical and biochemical follow-up 1
• Monitor for cerebrospinal fluid leak (rhinorrhea) due to medication-induced tumor shrinkage, particularly in tumors that have invaded the sphenoid bone 1
• For patients on >2 mg/week of cabergoline, annual echocardiography is recommended due to potential cardiac valvulopathy risk 2

Common Pitfalls and Caveats

• Small nocturnal dose increments can effectively reduce gastrointestinal side effects and postural hypotension 1
• Psychological side effects (mood changes, depression, aggression, hypersexuality) may occur and appear to be more common in children and adolescents 1
• Long-term studies show that complete normalization of prolactin levels rarely occurs in resistant cases, even with high-dose cabergoline treatment over many years 6
• After treatment discontinuation, monitor prolactin levels at 3-6 month intervals initially, as biochemical relapse often occurs within the first 2 years 1