Pre-operative dopamine agonist therapy improves post-operative tumor control following prolactinoma resection

Objective Normalization of serum prolactin concentrations in patients with prolactinomas is an accepted endpoint of therapy. Clinical signs and symptoms of hyperprolactinemia are usually resolved when prolactin levels are lowered to within the normal range. While most patients are treated with dopamine agonist drugs, some patients require surgical resection of their tumors. We sought to determine whether preoperative treatment with dopamine agonists alters the outcome of surgical intervention. Methods and results We present an analysis of 253 patients with prolactinomas treated surgically during the period of time when dopamine agonist therapy was first introduced and prior to its widespread use as first-line therapy. We compared both short- and long-term outcomes of patients treated with dopamine agonists prior to surgery with those undergoing surgery as their initial treatment modality. Our data showed that that patients treated with dopamine agonists prior to surgery experienced greater reductions in prolactin levels, had lower prolactin levels, were more likely to have normal prolactin levels at long term follow-up, and were less likely to require additional therapy to control their prolactin levels. Conclusion Our study provides strong evidence suggesting that, regardless of initial prolactin level, preoperative dopamine agonist therapy is not detrimental. In fact, pretreatment with dopamine agonist drugs, possibly by inducing tumor regression, seemed to improve the surgeon's ability to resect a greater percentage of the tumor and led to better control of the prolactin level.