Long-Term Clinical Outcomes of Invasive Giant Prolactinomas after a Mean Ten-Year Followup

Abstract

Objective . The aim of this study is to observe clinical outcomes after more than ten years of followup in a group of patients with invasive giant prolactinomas (IGPs) treated with dopamine agonists (DAs). Methods . Twenty-five patients met the criteria of IGPs, among which 16 patients primarily received bromocriptine (BRC) and the other nine had undergone unsuccessful microsurgery prior to BRC treatment. Results . After a mean follow-up period of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn fontstyle="italic">135.5</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">4.7</mml:mn></mml:math>months, the clinical symptoms in all patients improved by different degrees. Tumor volume was decreased by a mean of 98.6%, and the tumors of 19 patients had almost completely disappeared. The mean duration of treatment at maximal doses of BRC was 48.5 months. At the last follow-up visit, nineteen patients had normal PRL levels, and 14 of these patients had received the low-dose BRC treatment (at an average of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mn mathvariant="normal">2.9</mml:mn><mml:mo>±</mml:mo><mml:mn mathvariant="normal">0.3</mml:mn><mml:mo> </mml:mo><mml:mi mathvariant="normal">m</mml:mi><mml:mi mathvariant="normal">g</mml:mi><mml:mo>/</mml:mo><mml:mi mathvariant="normal">d</mml:mi></mml:math>). Younger patients &lt; 25 years had a significantly higher rate of persistent hyperprolactinemia after long-term BRC treatment (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.043</mml:mn></mml:math>). Conclusion . DAs are a first-line therapy for IGPs because they can effectively achieve long-term control in both shrinking tumor volume and normalizing the PRL level, and majority of patients need low-dose DA maintenance. Younger patients are prone to persistent hyperprolactinemia despite long-term DA treatment.