The role of temozolomide in the treatment of aggressive pituitary adenomas and pituitary carcinomas

The role of temozolomide in the treatment of aggressive pituitary adenomas and pituitary carcinomas Except for aggressive prolactinomas, which are could be treated with dopamin agonists, surgery is the first-line treatment option for most aggressive pituitary adenomas, but usually, due to their size, invasion of surrounding tissues, and high frequency of regrowth, they are difficult to treat with standard treatment paradigms, including surgery and radiotherapy. Pituitary carcinomas are rare tumours, and are defined by aggressive adenomas with brain and/or systemic metastasis. These carcinomas are highly aggressive, resistant to surgery, radiotherapy and systemic chemotherapy, and are associated with poor survival. Recently, temozolomide, an alkylating imidazoltetrazine derivative, chemically related to dacarbazine, have been used successfully in the management of aggressive pituitary adenomas and pituitary carcinomas, resistant to conventional treatments. O-6 methylguanine DNA methyltransferase, a DNA repair enzyme, have been demonstrated to be associated with sensitivity to temozolomide. Temozolomide is considered to be a novel drug in the treatment of aggressive pituitary adenomas and pituitary carcinomas, with few side effects, however it may cause serious side effects and proper follow-up of patients is essential.