P21.07 Temozolomide for Progressive Pituitary Adenomas Refractory to Surgery and Radiation: A Case Series

Abstract

AbstractIntroduction:Treatment of aggressive pituitary adenomas typically involves a multimodality approach based on histopathological features and may include pharmacotherapy, surgery and radiation therapy. In cases of treatment-refractory tumor progression, chemotherapy may be considered. However, no standard chemotherapeutic regimen has been established. Anecdotal reports suggest that temozolomide may have a beneficial role in a subset of cases.Materials and Methods:In this case series and institutional experience we report the outcome and unique clinical characteristics of seven patients with aggressive pituitary tumors treated with temozolomide given at various dose regimens.Results:Tumor pathology included somatotrope (n=1), corticotrope (n=3), and lactotrope (n=3) tumors. Four of the seven patients had at least two prior resections, and all had prior radiation and surgery before treatment with temozolomide was considered. Notably, all patients showed response to therapy, defined as either stable disease (43%) or partial response (57%), using standard tumor response assessment parameters. Excluding the two patients who remain on therapy to date, total duration of therapeutic benefit ranged between 5–15 months. Three patients showed radiographic and clinical benefit beyond one year.Conclusions:Our data suggest that temozolomide may have an important role in the management of aggressive functioning pituitary tumors that are resistant to standard therapies, and that optimization of therapy with temozolomide may involve individualized regimens. Future prospective clinical trials should be considered.