Outcome of drug treatment in patients with prolactinoma

ABSTRACT

Aim: Prolactinoma is the most common pituitary adenoma, accounting for about one third of patients with pituitary tumors. Therapeutic options include drug treatment, pituitary surgery, and radiotherapy. However, medical therapy is the preferred initial therapy for most patients with prolactinoma. The aim of the present work was to study patients with prolactinoma attending the Mansoura University Hospital from the clinical, biochemical and radiologic aspects, and to assess the efficacy and outcome of drugs used [bromocriptine and quinagolide] in their treatment. Subjects and A series of 29 cases with prolactinoma attending the Endocrinology outpatient clinic and inpatient department at the Mansoura University Hospital, during the period from 1998 to 2001, were analyzed retrospectively. Patients were followed up for a mean of 6 months to one year. Diagnosis of prolactinoma was made on the basis of high serum prolactin levels with pituitary mass lesion, after exclusion of high GH and high TSH serum levels. Patients had full sheets of clinical data, together with biochemical profile including serum prolactin level, TSH, basal GH. Magnetic resonance imaging [MRI] was done at diagnosis and at follow up. Fundus examination and field of vision were done for patients with macroprolactinoma, at diagnosis and follow up. Bromocriptine [B] was given to 21 patients [15 with microprolactinoma and 6 with macroprolactinoma] in a dose of 7.5-15 mg/day in divided doses, while quinagolide [Q] was given to 8 cases [4 with micro-and 4 with macroprolctinoma] in a dose of 1.5-3 mg once a day. Follow up was made for 6-12 months with clinical, biochemical and MRI assessment. It was found that about 2/3 of prolactinoma patients were females. Microprolactinoma was more prevalent in women while macroprolactinoma was more prevalent in men, and in general, microprolactinoma was more prevalent than macroprolactinoma. The clinical presentation was mainly related to hypogonadism in the form of amenorrhea-galactorrhea in women and sexual impotence and infertility in men. Serum prolactin level was significantly higher in macroprolactinoma compared to microprolactinoma. Visual field defects were found in 5 out of 10 patients harboring macro-prolactinoma. There was no significant difference in efficacy between bromocriptine and quinagolide. Normalized serum prolactin was achieved in 14 out of 15 patients with microprolactinoma in the B treated group versus 4 out of 4 patients in the Q treated group, and 4 out of 6 patients with macroprolactinoma in the B treated group versus 3 out of 4 patients in the Q treated group. Microprolactinoma disappeared in 6 cases out of 15 patients in the B treated group versus 3 out of 4 patients in the Q treated group. More than 50% reduction in tumor dimensions was achieved in 6 out of 15 patients in the B treated group versus 3 out of 4 patients in the Q treated group, and less than 50% reduction in tumor dimensions was achieved in 3 patients in the B treated group. Response to both drugs was not statistically different. For macroprolactinomas there was also a nonsignificant difference in the response to both drugs used. More than 50% reduction in tumor dimensions was achieved in 4 out of 6 patients in the B treated group versus 2 out of 4 patients in the Q treated group, while less than 50% reduction in tumor dimensions was achieved in one patient in the B treated group versus 2 patients in the Q treated group. One patient with macroprolactinoma was resistant to bromocriptine without change in adenoma dimensions. Visual field defects improved in 4 macroprolactinoma cases with prior field defects with the exception of the failed case in the B treated group. Drug side effects were more severe in bromocriptine-treated patients than quinagolide, and three patients of the series were switched to quinagolide because of bromocriptine intolerance. Conclusions: It can be concluded that prolactinoma is more prevalent in females predominantly microprolactinoma. When males are affected macroprolactima predominates due to delayed diagnosis. Patients with prolactinoma respond well to medical treatment in terms of normalization of excess prolactin level and reduction or disappearance of the tumor mass. Both bromocriptine and quinagolide are similarly effective, but quinagolide has fewer side effects