Preoperative Dopamine Agonist Therapy Improves Postoperative Tumor Control Following Prolactinoma Resection

Goals of treatment for patients with prolactinomas include normalization of serum prolactin concentrations, reduction in tumor size, resolution of any visual deficits, restoration of sexual function and fertility, and resolution of galactorrhea.

In most cases, these goals can be achieved by treatment with dopamine agonist drugs such as cabergoline or bromocriptine. Some patients, however, are intolerant of these medications or else choose surgery as definitive therapy so as to avoid life-long medical treatment. There has been considerable controversy regarding the effects of treatment with dopamine agonists on surgical success rates amid reports of drug-induced fibrosis of the gland and tumor that may lead to poor surgical outcomes.

To determine whether preoperative treatment with dopamine agonists alters the outcome of surgical intervention, CCPD investigators analyzed the outcomes of 253 patients who underwent surgery for prolactinomas when dopamine agonist therapy was first introduced. We compared both short-term and long-term outcomes of patients treated with dopamine agonists prior to surgery against the outcomes of patients undergoing surgery as their initial treatment modality.

The results showed that patients treated with dopamine agonists prior to surgery experienced greater reductions in prolactin levels, had lower overall 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. This study provides strong evidence that regardless of initial prolactin level, preoperative dopamine agonist therapy is not detrimental and, in fact, pretreatment with dopamine agonist drugs seems to improve the surgeon’s ability to resect a greater proportion of the tumor and leads to better long-term control of the hyperprolactinemia.

The results of this study were published in a 2008 issue of Pituitary