Addition of Epirubicin As a Third Drug to Carboplantin-Paclitaxel in First-Line Treatment of Advanced Ovarian Cancer : A Prospectively Randomized Gynecologic Cancer Intergroup Trial by the Arbeitsgemeinschaft Gynaekologische Onkologie Ovarian Cancer Study Group and the Groupe d'Investigateurs Nationaux pour I'Etude des Cancers Ovariens