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 thre

e 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

P0.01). 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.