Risk factors for central nervous system metastasis in patients with metastatic breast cancer

Abstract

Patients with metastatic breast cancer (MBC) and central nervous system (CNS) involvement have an impaired survival and quality of life. In this study, we investigated the risk factors for CNS metastasis among patients with MBC. The risk factors for development of CNS metastasis were analyzed in 154 patients with MBC. Expression of c-erbB-2, Ki-67, p53, and hormone receptors was examined by immunohistochemistry (IHC) in breast cancer tissue samples from the 154 patients. Kaplan-Meier and log-rank tests were used for the analysis of overall survival (OS). Chi-square test was used for univariate analysis. Median OS was significantly poorer for patients with CNS metastasis as compared with patients with no CNS metastasis (OS, 23 mo vs 30 mo, respectively;p = 0.03). Ki-67 and p53 overexpressions by IHC, and lung metastasis as the first site of relapse, were associated with a higher risk of developing CNS metastasis in the univariate analysis (p <or= 0.05). The presence of lung metastasis (odds ratio [OR]= 2.82, 95% confidence interval [CI]: 1.13-7.00,p = 0.02) and p53 overexpression (OR = 2.44, 95% CI: 0.99-6.00,p = 0.05) were the two predictive factors associated with occurrence of CNS metastasis in the multivariate analysis. In this study, the presences of lung metastasis as the first site of relapse and p53 overexpression were predictive for the occurrence of CNS metastasis in patients with MBC. Life expectancy of patients with CNS metastasis is significantly shorter than those without CNS metastasis. These results may have clinical significance in counseling MBC patients with regard to their prognosis.