Long-term outcome and MGMT as a predictive marker in 24 patients with atypical pituitary adenomas and pituitary carcinomas given treatment with temozolomide.
Författare
Summary, in English
Context/Objective: Locally aggressive pituitary tumors (LAPT) and pituitary carcinomas respond poorly to conventional therapy and cytotoxic drugs. Temozolomide (TMZ) is an oral alkylating drug with good tolerability, approved for treatment of malignant gliomas. The experience of its use in pituitary tumors is limited. Design/Setting: We report on 24 patients with aggressive pituitary tumors (16 LAPTs, 8 carcinomas) treated with TMZ for a median of 6 months (range 1-23). Follow-up ranged from 4 to 91 months, median 32.5 months. 19/24 tumors were hormone secreting (PRL 9, ACTH 4, GH 4, GH/PRL 2). Ki-67 was 2-23% in LAPTs, and 5-90% in carcinomas. Main outcome: Response to TMZ and the association with tumor expression of O6-methylguanine DNA methyltransferase (MGMT), MLH1, MSH2, and MSH6, examined by immunohistochemistry. Results: Complete tumor regression occurred in 2 carcinomas and persisted at follow-up after 48 and 91 months, respectively. Partial regress of tumor mass ranging from 35-80% occurred in 5 LAPTs and 2 carcinomas. Another patient with LAPT had a 71% decrease in prolactin levels without change in tumor volume. Three LAPTs could not be evaluated. Median MGMT staining was 9% (5-20%) in responders vs 93% (50-100%) in non-responders. Loss of MSH2 and MSH 6 was observed in a single patient who had a rapid development of resistance to TMZ. Conclusions: This study shows that TMZ is a valuable treatment option for patients with uncontrolled pituitary tumors. The data suggest that tumoral MGMT staining below 50% is associated with a high likelihood of treatment response.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Sidor
1689-1698
Publikation/Tidskrift/Serie
Journal of Clinical Endocrinology and Metabolism
Volym
100
Issue
4
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Oxford University Press
Ämne
- Endocrinology and Diabetes
Status
Published
Forskningsgrupp
- Genomics, Diabetes and Endocrinology
ISBN/ISSN/Övrigt
- ISSN: 1945-7197