NIMG-07. BEYOND RANDOM AND NUMERIC LESIONS: DIFFERENT IMAGING PATTERNS OF CENTRAL NERVOUS SYSTEM METASTASIS BASED ON PRIMARY TUMOR LOCATION AND MOLECULAR PROFILE

The purpose of this exhibit is to discuss different imaging patterns of central nervous system (CNS) metastasis based on their primary cancer site and to review the recent literature of the particularities of CNS metastasis distribution in the era of molecular advancement in oncology. Selected cases extracted from our institutions database will be presented. The cases will be didactically organized to illustrate the most common imaging characteristics and distribution of brain metastasis based on their organ of origin, such as lung, breast, renal, skin, testicle and gastrointestinal tract. (SCHROEDER T. et al., J Neurooncol. 2020). We will also discuss the correlation between tumor imaging findings and genetic profile. We intend to review well-known CNS metastasis imaging patterns, as preferential involvement of the posterior fossa and anatomic watershed areas in cases of lung cancer (TAKANO, K. et al. Neuro-Oncology, 2016) and the rarity of parenchyma metastasis from prostate cancer (HATZOGLOU V. et al, J Neuroimaging. 2014). We will also demonstrate newly described imaging findings in correlation with primary tumors genetic mutations, such as higher incidence of leptomeningeal involvement in triple negative breast cancer and increase in the number of brain lesions in cases of EGFR positive lung cancer. Familiarity with the most prevalent imaging characteristics of central nervous system metastasis helps oncologists and radiologists not to miss out a CNS progression in case of a known tumor, and also helps to direct systemic investigation of a primary tumor when brain metastasis is the initial presentation. The correlation between molecular profile and the most common sites of CNS involvement can help on treatment planning, including brain radiation (Yanagihara TK,et al., Tomography. 2017), and also bring to discussion the mechanisms of tumor dissemination, which can be targets for future treatments.

AKT1 is differentially expressed in primary tumors and brain metastases in humans with breast cancer.

Metastasis to the brain is a clinical problem in patients with breast cancer (1-3). We mined published microarray data (4, 5) to compare primary and metastatic tumor transcriptomes to discover genes associated with brain metastasis in patients with metastatic breast cancer. We report here the differential expression of the protein kinase AKT1 in the primary tumors and brain metastases of humans with breast cancer. AKT1 mRNA was present at significantly increased quantities in brain metastatic tissues as compared to primary tumors of the breast. These data combined suggest that up-regulation of AKT1 is a conserved event, both during transformation of breast tissues and progression to central nervous system metastasis and further point to potential importance of AKT1 modulation during progression of human breast cancer.