Evaluation of temozolomide (TMZ) activity in a mouse model of brain metastases (BM) from breast cancer (BC)

12014 Background: Cerebral metastases are observed in ∼15% of BC patients within 2 years from diagnosis. Recently, there has been an increase in the incidence of BM, likely due to increased survival achieved with novel therapies. Overexpression of HER2 is a significant risk factors associated with BM that cannot be efficiently controlled by trastuzumab. The objective of this study was to develop a mouse model of BC BM, in order to evaluate the efficacy of TMZ in controlling development & growth of the metastases. Methods: We developed an in vivo model, a MCF7 BC cell line (stably transfected with a luciferase reporter vector), intracranially injected at day 0 in immunodeficient mice. There were 3 groups of mice. Group 1 (n=5) no treatment; Group 2 (n=6) was treated with oral TMZ, 150 mg/m2 body surface, day 1–7; Group 3 (n=6) the same treatment, day 8- 14. All animals were sacrificed at day 30. Tumor growth was monitored by bio imaging (Xenogen Ivis 200) and by NMR. Histopathologic analysis was performed ...