RNA was isolated from 298 formalin-fixed paraffin-embedded tumor tissue samples from the HeCOG 10/97 ( HE10/97 ) trial , evaluating adjuvant dose-dense sequential chemotherapy with epirubicin followed by cyclophosphamide , methotrexate and 5-fluorouracil therapy with or without paclitaxel ( E-T-CMF vs. E-CMF ) .