Ovarian Epithelial Cancer Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Stage III and Stage IV Ovarian Epithelial Cancer Treatment
Table 2. Paclitaxel/Platinum Combinations Versus Comparator Arms in Trials continued...
Consolidation and/or maintenance therapy
Trials of consolidation and/or maintenance therapy have been carried out with drugs that contribute to the treatment of recurrent ovarian cancer. Presently, not one of the treatments given after the initial platinum/paclitaxel induction has been shown to improve survival; these treatments include the following:
- IP cisplatin (four cycles).
- Yttrium-labeled radioimmunoconjugate plus IP chemotherapy.
- IV topotecan (four cycles).
- Oregovomab vaccination (randomized trial vs. placebo).
- High-dose chemotherapy with hematopoietic support.
- Monthly paclitaxel (12 cycles).[33,34]
- Olaparib, an oral poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor (phase II trial).
A GOG-178 study of 277 patients compared three doses versus twelve doses of monthly paclitaxel given every 4 weeks following a clinically defined complete response at the time of completion of platinum/paclitaxel induction. However, the study was stopped early because of a very significant difference in PFS (28 months vs. 21 months).[Level of evidence: 1iiDiii] Subsequent updates of this data have raised the possibility that a subset of patients with low CA 125 levels might show a survival benefit. A trial to confirm the value of maintenance with taxanes versus observation is being conducted by the GOG.
A smaller Italian study entered 200 patients over 7 years who were randomly assigned to either 12 similar courses of monthly paclitaxel or observation; patients were in clinical complete response (n = 95) or pathologic complete response (n = 105) after induction therapy at the time of their random assignment. Sensory neuropathy was the most prominent toxicity and was grade 2 in 21.3% of the patients and grade 3 in 6.7% of the patients. The median PFS for the maintenance paclitaxel arm was 34 months (95% CI, 20–43 months) and 30 months (95% CI, 17–53 months) for the observation arm. Neither PFS nor OS differences were significant.
An accompanying editorial points out the weaknesses of both studies in order to draw conclusions (both stopped early and were noninformative for survival endpoint). Also, although both studies addressed the issue of maintenance paclitaxel administered monthly, the patient populations differed. This was reflected by the considerably better outcome in both arms of the Italian study. Taken together, paclitaxel maintenance is of unproven value and requires validation by the ongoing and larger GOG-178 study cited above.
Two phase III trials (GOG-0218 [NCT00262847] and ICON 7 [NCT00483782]) have evaluated the role of bevacizumab in first-line therapy for ovarian, fallopian tube, and primary peritoneal cancers following surgical cytoreduction.[38,39] Both trials showed a modest improvement in PFS when bevacizumab was added to initial chemotherapy and continued every 3 weeks for 16 and 12 additional cycles, respectively, as a maintenance phase.