[Histological changes and operative findings of pituitary adenomas after bromocriptine treatment]

Surgical outcomes of medically failed prolactinomas: a systematic review and meta-analysis

PURPOSE

In Prolactinomas, surgery or radiation are reserved for DA failure due to tumor resistance, intolerance to medication-induced side-effects, or patient preference. This systematic review and meta-analysis summarizes the currently available literature regarding the effectiveness of surgery to treat prolactinomas in patients who have failed DA therapy.

METHOD

A literature search was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies that reported outcomes of medically resistant and intolerant prolactinoma treated surgically.

RESULTS

10 articles (Total N = 816, Surgery N = 657) met the inclusion criteria. 38% of patients who underwent surgery following DA failure achieved remission without need for further treatment (p < 0.001, I² = 67.09%) with a median follow-up of 49.2 +/- 40 months. 62% achieved remission with multimodal treatment (p < 0.001, I² = 93.28%) with a median follow-up of 53 +/- 39.8 months. 16% of cases demonstrated recurrence after early remission (p = 0.02, I² = 62.91%) with recurrence occurring on average at 27 +/- 9 months. Overall, 46% of patients required reinstitution of postoperative DA therapy at last follow up (p < 0.001, I² = 82.57%). Subgroup analysis of macroprolactinoma and microprolactinoma has demonstrated that there is no statistical significance in achieving long-term remission with surgery stand-alone in macroprolactinoma group (p = 0.49) although 43% of patients were able to achieve remission with multimodal therapy at last follow-up in the same group (p < 0.001, I² = 86.34%).

CONCLUSIONS

This systematic review and meta-analysis revealed 38% of operated patients achieved remission, while 62% achieved remission when additional modes of therapy were implemented. Therefore, although surgery has not been initial therapeutic choice for prolactinoma, it plays a significant role in medically failed prolactinoma care.

Cabergoline-induced fibrosis of prolactinomas: a neurosurgical perspective

Presently, the standard of care for prolactinomas, a type of pituitary adenoma, is dopaminergic agents such as bromocriptine and cabergoline. However, dopaminergic agents may induce fibrosis of cardiac valves leading to valvular insufficiency, necessitating surgical treatment of prolactinoma. Fibrosis of prolactinoma can be induced by prolonged medical treatment with bromocriptine, and this usually occurs after years of treatment. In comparison to bromocriptine, there have been no reports of cabergoline-induced fibrosis of prolactinoma. There is a potential for greater emphasis to be placed on assessing the tumour consistency from preoperative MRI scans, or even preoperative contrast-enhanced 3D Fast Imaging Employing Steady-state Acquisition imaging to allow better planning of the surgery. We report a rare case of fibrosis of prolactinoma after cabergoline treatment resulting in its subsequent difficult surgical removal. This patient had early MRI changes of fibrosis of prolactinoma after a short period of 6 months of cabergoline treatment.

Effect of dopaminergic drug treatment on surgical findings in prolactinomas

It has been reported that prolactinomas treated with Bromocriptine (BROM) show fibrosis that may interfere with complete surgical resection. The same has not been reported for Cabergoline (CAB). We retrospectively studied 24 consecutive patients (13 females, mean age 40 years, range 16-60) with histopathologically confirmed prolactinomas undergoing surgical resection at Johns Hopkins Hospital between 1992 and 2009. We compared these prolactinomas to 34 patients (22 females, mean age 42.9 years, range 15-75) with GH-secreting adenoma. The operative notes from 7 different neurosurgeons were reviewed to catalog the tumors as fibrous or not fibrous. Of the 24 prolactinomas, 21 (87.5%) were previously treated with DA. Indication for surgery was: DA resistance (n.5), DA intolerance (n.6), persistent mass effect (n.7) and CSF leak (n.3). Five (14.7%) of GH-secreting adenomas, were exposed to DA and/or somatostatin analogs. We found that 54% of prolactinomas and only 6% of GH-secreting adenomas were described as fibrous. 10/12 (77%) of prolactinomas exposed to BROM for at least 1 month, 2/9 (22%) exposed to CAB only, and 1/3 (33%) not previously treated were fibrous (P < 0.05). The mean BROM cumulative dose was 406 mg (range 75-1,375), while CAB dose was 28 mg (range 6-70). Only 18% of non-fibrous prolactinomas had been exposed to BROM. Only 3 patients had persistent biochemical remission (2 treated with CAB and 1 not treated). Patients exposed to BROM for at least 1 month are more likely to have tumor fibrosis than patients that are untreated or treated with CAB.