Role of HER2 in Brain Metastasis of Breast Cancer: a Systematic Review and Meta-Analysis

Background: Breast cancer is one of the most common cancers among women worldwide and the HER2receptor plays an important role in its development and progression. This systematic review aimed to summarizethe role of HER2 in brain metastasis in patients with breast cancer. Materials and
Methods: We conducted aliterature search by advanced search in title field using the Scopus, Pubmed, and Google scholar databasesuntil the end of June 2014. With metastasis, metastatic, HER2, brain, and breast cancer, as terms of search weselected 31 articles, which were reviewed by two independent and blinded expert reviewers. The studies werefirst selected according to their titles and abstracts. Quality of the studies were then assessed using the STROBE(Strengthening the Reporting of Observational Studies in Epidemiology) protocol for observational studiesand CONSORT(Consolidation of Standards for Reporting Trials) protocol for clinical trials. For statisticalanalyses, we used STATA, version 11.0 software. Forest and funnel diagrams were drawn and for heterogeneity,index was also considered. Also we used meta regression analysis.
Results: Finally, we reviewed 10 studies. Theprevalence of brain metastasis in HER2- positive breast cancer patients was 24.9%. There was publication biasin the reviewed studies. Meta regression analysis showed that follow up time had no significant effect (p=0.396)on the prevalence of brain metastasis.
Conclusions: The results showed a high prevalence of brain metastasis inHER2 positive breast cancer patients.