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 HER2 receptor plays an important role in its development and progression. This systematic review aimed to summarize the role of HER2 in brain metastasis in patients with breast cancer.


METHODS
We conducted a literature search by advanced search in title field using the Scopus, Pubmed, and Google scholar databases until the end of June 2014. With metastasis, metastatic, HER2, brain, and breast cancer, as terms of search we selected 31 articles, which were reviewed by two independent and blinded expert reviewers. The studies were first 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 studies and CONSORT(Consolidation of Standards for Reporting Trials) protocol for clinical trials. For statistical analyses, 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. The prevalence of brain metastasis in HER2- positive breast cancer patients was 24.9%. There was publication bias in 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 in HER2 positive breast cancer patients.
Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran E-mail : reza_nava@yahoo.com.
Akbar
A
Hedayatizadeh-Omran
Alireza
A
Rafiei
Reza
R
Alizadeh-Navaei
Mohsen
M
Tehrani
Reza
R
Valadan
Kambiz
K
Moradzadeh
Mohammad
M
Panbechi
Seyed Mehdi
SM
Taghavi
D001932:Brain Neoplasms / Q000378:metabolism / Q000556:secondary*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012307:Risk Factors
D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human