Breast Cancer / Gene expression / Database Management Systems / Biological Sciences / Humans / Mathematical Sciences / BMC Bioinformatics / Sample Size / Prognosis / Data Aggregation / Reproducibility of Results / Statistical Model / Side Effect / Large Scale / Health Care Expenditure / Sensitivity and Specificity / Microarray Data / Gene expression profiling / Gene Expression Data / Mathematical Sciences / BMC Bioinformatics / Sample Size / Prognosis / Data Aggregation / Reproducibility of Results / Statistical Model / Side Effect / Large Scale / Health Care Expenditure / Sensitivity and Specificity / Microarray Data / Gene expression profiling / Gene Expression Data