Prolactin secreting pituitary adenomas: analysis of 429 surgically treated patients, effect of adjuvant treatment modalities and review of the literature.

OBJECTIVE

We performed this retrospective analysis to determine the efficacy of surgery and radiotherapy over hormonal and volumetric control of prolactinomas, many of which had failed during dopa-agonist therapy. In the same analysis, the efficiency of topical bromocriptine application as a preliminary study was compared with standard treatment modalities.

MATERIALS AND METHODS

Between 1982-1997, 429 prolactinoma patients who underwent surgery at Hacettepe University Neurosurgery Department and at Bayindir Medical Center were included in this study. All patients were classified according to Hardy's classification scheme and were further divided into 'invasive' and 'non-invasive' groups based on this radiological classification system. The mean follow-up time was 38.4 months. One hundred and thirty five patients had peroperative bromocriptine application into the sellar cavity and these, either receiving radiotherapy (RT) or not, were analysed separately from the other 294 patients. In the early post-operative period, 104 of these patients were given conventional radiotherapy with median dose of 4500 cGy. We focused on the effects of surgery and radiotherapy over volumetric and hormonal tumour control on the basis of invasion characteristics and the early results of topical bromocriptine application in macroprolactinoma patients; and compared our results with the literature.

RESULTS

Statistical analysis revealed that radiotherapy was not effective over hormonal and volumetric tumour control for prolactinomas. We did not observe any correlation to dural invasion of the sellar floor, recurrence, and the disease-free survival time. Topical bromocriptine application seemed to improve the volumetric control in 135 selected macroprolactinoma patients but not hormonal response compared with the standard treatment modalities.

CONCLUSION

Conventional radiotherapy is not as effective as expected for prolactinomas and should not be preferred considering its adverse effects. Tumoural infiltration of the sellar dura mater is not a prognostic criterion for recurrence expectation and, therefore, should not be a criterion for radiotherapy after surgery. After subtotal removal, postoperative dopa-agonist therapy should be considered even if the patient was intolerant or resistant to previous treatment since surgery seems to improve patients' drug tolerance and cooperation due probably to the lower dose requirement. The early results of topical bromocriptine application seem to improve volumetric tumour control but this should not be accepted as a judgement since we need to wait for later results and to expand the sample size for more reliable interpretation.