Dopamine agonist-resistant prolactinomas

Dopamine agonist-resistant prolactinomas
-Oh MC, Aghi MK Journal of Neurosurgery 2011 May;114(5):1369-79. published online January 7, 2011; DOI: 10.3171/2010.11.JNS101369.

• "Dopamine agonist-resistant prolactinomas exhibit aggressive behavior and tend to be large, invasive, hyperangiogenic tumors with high mitotic indices, which makes their management via surgery, radiosurgery, or alternative medical therapies challenging, thus underscoring the need for novel medical therapies or treatment regimens that target these lesions."
  
• "...slightly less than 10% of patients with prolactinomas do not experience normalization of their prolactin levels in response to dopamine agonists, and harbor tumors that are resistant to dopamine agonist therapy."
  
• "...a minimum pharmacological definition of dopamine agonist resistance would seem to require a failure to respond to 3 months of treatment with up to 3.5 mg of cabergoline per week."
  
• "Although very rare, secondary or acquired resistance to dopamine agonist therapy has also been described, in which patients who were initially responsive to... either bromocriptine or cabergoline, later develop dopamine agonist resistance, with elevated prolactin levels and sometimes an enlarging tumor volume several years after beginning treatment... According to a recent report... there have been only 5 reported instances of patients who demonstrated secondary resistance to dopamine agonist therapy (2 to bromocriptine and 3 to cabergoline).
  
• DARPs (dopamine agonist resistant prolactinomas) are more likely to exhibit cavernous sinus invasion... [71% vs 10% for dopamine agonist-responsive prolactinomas]."
  
• "DARPs typically do not metastatize."
  
• "Transsphenoidal surgery is recommended for prolactinomas instead of medical treatment if
  • ...2) inadequate prolactin reduction despite high cabergoline doses...
    
  • 3) a female patient desires fertility, which may not occur while on dopamine agonists...
    
  • 5) the patient cannot tolerate dopamine agonist therapy due to side effects.
• transsphenoidal surgery:
  • prolactin was normalized in 36% of patients with DARPs in one study.
    
  • prolactin was normalized in 75% of patients with DARPs that were microprolactinomas.
    
  • "Temozolomide... has been used to treat 3 patients with cabergoline-resistant DARPs... with good results in all 3 cases."

The Endoscopic Endonasal Transsphenoidal Approach to the Suprasellar Cistern

The Endoscopic Endonasal Transsphenoidal Approach to the Suprasellar Cistern
-Schwartz T, et al. Clinical Neurosurgery, Volume 54, 2007.

• Description of endoscopic transsphenoidal surgery.

Transsphenoidal Surgery for Pituitary Tumors in the United States, 1996–2000: Mortality, Morbidity, and the Effects of Hospital and Surgeon Volume

Transsphenoidal Surgery for Pituitary Tumors in the United States, 1996–2000: Mortality, Morbidity, and the Effects of Hospital and Surgeon Volume
-Barker F, II, et al. Journal of Clinical Endocrinology & Metabolism 88(10):4709–4719, ©2003 by The Endocrine Society, doi: 10.1210/jc.2003-030461

• Results of transsphenoidal surgery for pituitary tumors, as a function of hospital volume, surgeon volume, and more.

Endoscopic endonasal transsphenoidal surgery for functional pituitary adenomas

Endoscopic endonasal transsphenoidal surgery for functional pituitary adenomas
-Hofstetter C, et al. Neurosurg Focus 30 (4):E10, 2011

• Description of endoscopic endonasal transsphenoidal surgery.
• Results from the resection of 86 functional pituitary adenomas at Weill Cornell Medical College, New York–Presbyterian Hospital, from 2004-2010.