The present invention relates to genetic markers whose expression is
correlated with breast cancer. Specifically, the invention provides sets
of markers whose expression patterns can be used to differentiate
clinical conditions associated with breast cancer, such as the presence
or absence of the estrogen receptor ESR1, and BRCA1 and sporadic tumors,
and to provide information on the likelihood of tumor distant metastases
within five years of initial diagnosis. The invention relates to methods
of using these markers to distinguish these conditions. The invention
also provides methods of classifying and treating patients based on
prognosis. The invention also relates to kits containing ready-to-use
microarrays and computer software for data analysis using the diagnostic,
prognostic and statistical methods disclosed herein.