Objective: There is no standard treatment for recurrent epithelial ovarian cancer (EOC). As there are no curative options, many oncologists choose to treat women who recur with carboplatin, particularly if they are deemed to have platinum-sensitive disease. However, particularly in the era of platinum-taxane treatment as primary therapy, the utility of this treatment has not been established, nor is it clear whether the results of single-agent treatment are equivalent to that of combination therapy. We sought to determine the outcomes for patients with platinum-sensitive EOC who were treated with carboplatin-taxane therapy and received single-agent carboplatin (C) as second chemotherapy. In addition, we sought to compare these results to the outcomes in women who received carboplatin and paclitaxel (C + T) at first relapse.
Patients and methods: We identified 24 patients using our electronic institutional database with a histologically confirmed diagnosis of ovarian cancer that had a complete response to platinum-paclitaxel chemotherapy, relapsed greater than 6 months after treatment, and received single-agent carboplatin as second-line chemotherapy. We performed a subsequent comparison between a subgroup of this cohort and one that met the same inclusion criteria but received C + T at relapse between January 1998 and December 2000.
Results: Eighteen patients were evaluable for response, and all were available for analysis of survival end points. For evaluable patients, the overall response rate was 39% (complete, 11%; partial, 28%). Twenty-two percent had stable disease. Six (25%) patients experienced a hypersensitivity reaction, including 1 who required hospitalization. The median overall survival was 22 months. The 2-year overall survival rate was 49%. Stratification by treatment-free interval (TFI) showed a 25% for a TFI between 6 and 12 months and 43% for a TFI > 12 months. When a subgroup of these women (18/24) was compared to a cohort that received C + T (29), the combination was associated with a higher complete and overall response rate, 7 and 36% for C versus 45 and 71% for C + T (P = 0.02). The overall survival in women who received C was 26 months versus 42 months in the women who received C + T (P < 0.02).
Conclusion: Carboplatin as a single agent is effective therapy for recurrent ovarian cancer in women who recur following treatment with carboplatin and paclitaxel, and the treatment-free interval predicts response to single-agent carboplatin. However, our secondary analysis suggests that carboplatin and paclitaxel may produce a higher response rate and a survival benefit compared to C alone. This supports the conclusions of ICON4, which recently reported both overall and progression-free survival benefits with C + T over C in women with platinum-sensitive recurrent disease.