Survival data of Secondary Debulking efforts shows that it's best to have optimal debulking during the initial surgery or more than three cycles of chemotherapy following secondary debulking.  Read more below.

Secondary surgical cytoreduction for advanced ovarian carcinoma.
Rose PJ, Nerenstone S, Brady MF, Clarke-Pearson D, Olt G, Rubin SC, Moore DH, Small JM.
N Engl J Med. 2004; 351: 2489-2497. [Abstract]

Summary
Rose and coworkers, reporting for the Gynecologic Oncology Group, recently published a randomized prospective study of interval cytoreductive surgery for patients with advanced stage (Stage III and IV) epithelial ovarian cancer left with suboptimal residual disease after initial surgery. Five hundred fifty patients with suboptimal initial debulking were enrolled in this study, with 448 patients available for randomization after completing the initial 3 cycles of chemotherapy with carboplatin and paclitaxel. Patients were randomized to an attempt at interval debulking (n=226) or no interval surgery (n=222). Both groups then received an additional 3 cycles of carboplatin and paclitaxel chemotherapy. Among the patients in the investigational arm (interval surgery), 112 were found to have bulky persistent disease exceeding 1cm in diameter. Of these 112 patients, 79 (70%) were successfully cytoreduced to small-volume residual disease. Combining these patients with those found to have small-volume disease at interval surgery, a total of 83% of patients in the investigational arm were left with residual disease <1cm prior to resuming chemotherapy treatments. Comparing the interval debulking and no interval debulking groups, survival analysis revealed no statistically significant differences in progression-free survival (12.5 months vs 12.7 months) or overall survival (36.2 months vs 35.7 months).

Discussion
The results of this study contradict an earlier report by van der Burg et al (N Eng J Med 1995; 332: 629) that indicated a survival advantage associated with interval debulking (26 months vs 20 months median overall survival time). One of the inherent problems in assessing the survival impact of interval debulking is that these patients carry an inherently guarded prognosis based on the fact that their initial surgery was suboptimal. The study by Rose et al was very well designed and executed and conclusively demonstrates that the treatment strategy of ‘chemo-debulking’ patients with suboptimal disease with 3 cycles of therapy followed by a repeat attempt at debulking and 3 additional cycles of chemotherapy is not significantly better than 6 cycles of chemotherapy alone. Taken another way, this study demonstrates that 3 cycles of chemotherapy following a maximal attempt at cytoreduction for patients with advanced stage ovarian cancer is not sufficient to result in meaningful disease control. This is not surprising, since one would not expect to achieve significant disease control if only 3 cycles of chemotherapy were administered after an optimal initial (primary) debulking surgery (rather than the conventional 6 cycles).

Conclusion
These data suggest that interval cytoreductive surgery, when followed by only 3 cycles of additional chemotherapy, does not offer a survival advantage compared to 6 cycles of chemotherapy alone for patients undergoing a suboptimal initial debulking effort. Perhaps more than anything, this study highlights the need to optimize the patients’ chances for a successful initial surgery that achieves a minimum volume of residual disease. Specifically, such surgery should be concentrated in centers with the necessary expertise to perform such surgery safely, as oftentimes extensive resection is required. Secondly, the study by Rose et al reinforces the notion that to achieve a survival benefit following a maximal surgical effort, more than 3 cycles of adjuvant chemotherapy are necessary.