Triple negative breast cancer patients with brain metastasis are associated with more concurrent lung metastasis

Abstract

Background: Breast cancer is a heterogeneous disease with different molecular subtypes. It is known that triple negative breast cancer and the HER-2 positive breast cancer subtypes are associated with more brain metastases. We further explored different subtypes of breast cancer patients with brain metastasis and analyzed their clinical behaviour with particular reference to the Hong Kong Chinese population. Methodology: We reviewed all breast cancer patients with brain metastasis presented to the Department of Clinical Oncology in the Queen Mary Hospital, the University of Hong Kong which is a teaching hospital during January 2004 to June 2008. Sociodemographic factors, date of primary breast cancer diagnosis and the tumour features, clinical behaviour at presentation, treatment received such as surgery, chemotherapy, hormonal therapy and targeted therapy, time of local recurrence, metastasis including brain metastasis, the recursive partitioning analysis (RPA) classes and treatment for the brain metastasis were all recorded. We classified the patients into 3 main subtypes, hormone positive, triple-negative (TNC) and HER-2 positive subtypes and further studied the clinical features and brain metastasis behaviour. Statistical analysis using SPSS 16.0 version was applied. Results: Altogether, there were 60 breast cancer patients with brain metastasis occurred during January 2004 to June 2008 requiring further management in our Department. Hormone positive patients constituted 46.6% while TNC accounted for 15.5% and HER-2 positive patients accounted for 37.9% of the cohort. The majority presented with symptoms at the time of the brain metastasis (93.1%) with headache being the most common symptom (43.1%), and 54 patients received whole brain radiotherapy (WBRT) and 8 patients received surgical resection of the brain metastasis. There were no significant statistical significance between the breast cancer subtypes and the metastatic behaviour except that the TNC patients were associated with concurrent lung metastasis when they first presented with brain metastasis (p = 0.03) when compared to the hormone positive and HER-2 positive patients. The ANOVA analysis showed there was a statistically significant difference between the RPA Classes of the patients and their time of survival after the brain metastasis (p = 0.002). Further ANOVA Post Hoc showed the RPA Class 3 patients were associated with shorter time of survival after brain metastasis when compared to the Class 1 patients (2.4 months vs 11.8 months, p = 0.001). However, patients with brain metastasis and different breast cancer subtypes did not have statistically significant different time of survival after their brain metastases. Conclusion: Hong Kong Chinese triple negative breast cancer patients with brain metastasis were associated with more concurrent lung metastasis. The RPA Classification still serves as a prognostic indicator with reference to the survival after brain metastasis in the breast cancer patients when compared to the breast cancer subtypes. Further large-scale multi-centre epidemiology study is warranted to confirm the above findings.