Total Neoadjuvant 6 Cycles of Chemotherapy Versus 3 Cycles in Partial Responder Patients Diagnosed With Epithelial Ovarian Cancer

neoadjuvant chemotherapy in stage III and IV ovarian cancer is given in 3-4 cycles with patients who R0 surgical resection is less likely to occur, in this study will assess total neoadjuvant chemotherapy 6 cycles then interval debulking surgery (experimental arm) versus 4 cycles then interval debulking surgery (control arm) in patients who achieve partial response or stationary disease by imaging after 3- 4 cycles of neoadjuvant chemotherapy, investigators'' primary end points will be event free survival, safety and tolerability and time to relapse, our secondary end points will be overall survival and surgical morbidity and mortality