The prognosis analysis of different metastasis pattern in patients with different breast cancer subtypes: a SEER based study

// Haiyong Wang 1 , Chenyue Zhang 2 , Jingze Zhang 1 , Li Kong 1 , Hui Zhu 1 , Jinming Yu 1 1 Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Sciences, Shandong 250117, China 2 Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China Correspondence to: Li Kong, email: konglitexu@126.com Hui Zhu, email: drzhuhui@163.com Jinming Yu, email: sdzlyujinming@126.com Keywords: breast cancer, metastasis pattern, prognosis, breast cancer subtypes, SEER Received: September 27, 2016     Accepted: December 01, 2016     Published: December 27, 2016 ABSTRACT Studies on prognosis of different metastasis patterns in patients with different breast cancer subtypes (BCS) are limited. Therefore, we identified 7862 breast cancer patients with distant metastasis from 2010 to 2013 using Surveillance, Epidemiology, wand End Results (SEER) population-based data. The results showed that bone was the most common metastatic site and brain was the least common metastatic site, and the patients with HR+/HER2− occupied the highest metastasis proportion, the lowest metastasis proportion were found in HR-/HER2+ patients. Univariate and multivariate logistic regression analysis were used to analyze the association, and it was found that there were significant differences of distant metastasis patterns in patients with different BCS(different P value). Importantly, univariate and multivariate Cox regression analysis were used to analyze the prognosis. It was proven that only bone metastasis was not a prognostic factor in the HR+/HER2-, HR+/HER2+ and HR-/HER2+ subgroup (all, P > 0.05), and patients with brain metastasis had the worst cancer specific survival (CSS) in all the subgroups of BCS (all, P 0.05).