MLTI-01. Study on the Association between Prone Locations and Prognosis of Breast Cancer Brain Metastases via Voxel Analysis

Abstract Purpose This study aimed to analyze the preferred locations of secondary brain tumors of breast carcinoma according to different biological characteristics. Method 161 Breast cancer brain metastasis (BCBM) patients diagnosed between January 2007 and February 2018 were retrospectively analyzed. MR images when brain metastases occurred were collected, registered, segmented. The frequency and p-value heatmaps were constructed to compare two biological phenotypes using two-tailed Fisher’s exact test. Age, treatments, the status of ER, PR, and HER2, luminal subtype, tumor marker levels in peripheral blood including CEA, CA19-9, and CA15-3 were statistically analyzed. Survival data were analyzed by Kaplan–Meier method, log-rank test, and multivariate logistic regression. Result The frequency heat map shows lesions of patients with BCBM are more inclined to the cerebellar hemisphere. Older patients(>49 years old, median age) mainly occur in the left frontal lobe, the right parietal lobe, and adjacent meninges comparing with white matter of the left parietal lobe, cerebellar vermis, and areas around the fourth ventricle among younger patients and the difference is significant. Patients with tumors located on the surface of the brain are more likely to undergo surgical treatment, however, conservative treatment was considered if metastases are located at the midline structure. ER and PR-positive and HER-2 enriched patients have more significance in metastases, at the left parieto-occipital junction area, frontal lobe, parietal lobe, cerebellar hemisphere, and adjacent meninges. Metastases with high levels of CEA are found significantly at areas around the central anterior gyrus. Lesions with an elevated level of CA19-9 and CA15-3 tend to be frontal, parietal, and occipital. Besides, HER-2 enriched in primary sites and a normal level of CA15-3 in peripheral blood were two independent protective factors in determining prognostic outcomes. Conclusion The preferred locations of BCBM could be clues of further study and helpful for clinical strategies.