Treatment of Postsurgical Clinically Nonfunctioning Pituitary Adenomas Remnants With Cabergoline

Background: The standard first-line therapy for clinically nonfunctioning adenomas (NFPA) is transsphenoidal surgery, however there is no consensus of the optimal postsurgical treatment for residual adenoma. Medical therapy, such as cabergoline (CAB), may be an alternative for preventing growth of postoperative pituitary tumor remnants. The moment of introduction dopamine agonist (DA) is still uncertain. Objective: To assess tumor behavior in patients who used CAB in the postoperative period. Design and methods: A retrospective cross-sectional study was performed with twenty one patients with NFPA treated surgically. All patients stayed with residual tumor and were divided in two groups: patients who received CAB early in postoperative period (Group A, n=6) and when tumor growth were detected during follow-up (Group B, n=15). CAB dosage was 1.5mg or 3.5mg per week. A change in tumor size was considered significant and recorded as such if a difference of at least 5 mm in major diameter was observed. MRI was performed four months after surgery and yearly thereafter in all patients. Subjects in treatment groups also underwent MRI 6 months following medical therapy. No patients were treated by irradiation before or during the follow-up. Statistical analysis was performed using the Fisher’s exact test. Results: From 21 patients, 11 were men and 10 women with similar mean age in two groups (p=0.651). MRI in group A showed stabilization of residual tumor in 50% (3/6) and tumor reduction in 50% (3/6) in group A. In group B, tumor shrinkage was observed in 47% (7/15), stabilization in 27% (4/15) and enlarged in 27% (4/15). No statistical difference between groups was obtained regarding tumor shrinkage and stabilization with the treatment (Group A n=6 versus Group B n=11, p=0.281). In contraste Batista et al., 2016, have already shown that CAB was effective alternative in residual tumor reduction in a study with 74 patients. Conclusion: A multicenter study is necessary to define the role of CAB in the treatment of residual tumor in postsurgical patients with NFPA.