To assess the efficacy of temozolomide in a series of three patients with pituitary neoplasms refractory to medical and surgical treatment.

There remains relatively little information on the use of temozolamide for pituitary neoplasms, with no control studies performed to date. Less than 50 cases of pituitary adenoma (including both ACTH-secreting and prolactin-secreting tumors) treated with temozolamide have been reported, with response rates up to 50-75% depending on criteria. 

A retrospective review was conducted of patients at our institution with pituitary adenomas refractory to standard therapies and treated with temozolomide. Charts were reviewed for clinical, imaging, and hormonal response to temozolamide therapy. 

Patient ages ranged from 20-70 years and included two females and one male. Each had undergone surgery and medical therapy (bromocriptine, cabergoline, ketoconazole, mitotane, and/or pasireotide), and two had received radiation. Pathology had demonstrated prolactinomas in two patients and Cushing’s disease in the third patient. Temozolomide was administered in each case because of refractory tumor. Each patient showed improvement in clinical symptoms. Prolactin level declined from 222.8 to 81.9 ug/L over 9 months in one patient. There was no change in the ACTH at 7 months since initiation of therapy in the patient with Cushings disease. MRI is stable in both of these patients. The third patient has not yet had laboratory or imaging follow-up. 

There are still relatively few published cases of pituitary adenomas treated with temozolomide; data suggests that the majority of patients treated have a favorable response. In our case series each patient had a good clinical response and one has had a significant decline in serum prolactin. Temozolomide is a viable option for patients with pituitary adenomas that are refractory to standard therapy.