Ferreira-Hermosillo A, Ramos-Bustamante L, Ramírez-Rentería C, Mercado M, Mendoza-Zubieta V

Language: Spanish
References: 9
Page: 163-166
PDF size: 98.74 Kb.

ABSTRACT

Prolactinomas are the most common pituitary tumors. Dopamine agonists (DA) are the treatment of first choice. The goal of treatment is the restoration of the gonadal axis, and the prevention of neurological complications, particularly cranial nerve and chiasm compression. Resistance to AD is defined as inability to normalize PRL levels and the lack of tumor shrinkage by 50% after 4 months of treatment with cabergoline at doses 3 mg per week or more. The mechanisms involved in DA resistance are not well understood but some theories point towards the reduction in the transcription of the gene that encodes the dopamine receptor D2 (DRD2), as well as to post-receptor abnormalities. Cabergoline is the most effective DA, however 5 to 15% of prolactinomas may be resistant to this drug; tumors that do not respond to bromocriptine often respond to cabergoline. The presence of resistance to both DA is a great challenge. Resistant and invasive tumors may be candidates for surgical treatment, radiation therapy, somatostatine analoges or chemotherapy with temozolomide, though the effectiveness of this last has not been proved yet.

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