Abstract: Background and purpose: More than 70 percent of ovarian cancer patients were diagnosed in the advanced stage. Currently the 5-year disease free survival (DFS) of stage Ⅲ_C-Ⅳ ovarian cancer patients wsa about 10 percent after first line chemotherapy. This study aimed to improve the 5-year DFS by three-step chemotherapy according to the mechanisms of ovarian cancer biological characteristics, cytodynamics and pharmacology. Methods: In arm A, the patients received three-step chemotherapy after primary debulking surgery, step one with paclitaxel plus carboplatin (TC regimen), every 3 weeks for 6 to 8 cycles; step two with etoposide plus cyclophosphamide, every 4 weeks for 6 cycles; step three wit carboplatin plus cyclophosphamide every eight weeks for six cycles. In control arm B, we retrospectively analysed 51 cases with Ⅲ_C-Ⅳ stage ovarian cancer, who had completely response after standard chemotherapy with six to eight cycles of TC after primary surgery during 2007. We compared the 5-year DFS between the two arms. Results: The 5-year DFS of 15 cases in arm A was 80%(12/15), which was significantly higher than that of arm B (5.9%, 3/51, P<0.01). Conclusion: The three-step chemotherapy after optimal debulking surgery in stage Ⅲ_C-Ⅳ can improve the 5-year DFS. This regimen is high efficacy, mild side-effect witn low cost, which deserves further exploration.

Key words: Ovarian cancer, Cytoreductive surgery, Chemotherapy