Three versus six cycles of adjuvant platinum-based chemotherapy in early stage clear cell ovarian carcinoma – A multi-institutional cohort

Abstract

Objectives To determine if 6 versus 3 cycles of adjuvant platinum-based chemotherapy with or without taxane impacts survival in early stage ovarian clear cell carcinoma (OCCC). Methods We retrospectively identified all cases of stage I and II OCCC treated at 5 institutions from January 1994 through December 2011. Patients were divided into 2 groups: those who received 3 versus 6 cycles of adjuvant chemotherapy. Our cohort consisted of 210 patients with stage IA-II disease, 116 of whom underwent full surgical staging. Cox proportional hazards regression and Kaplan-Meier analyses were performed to evaluate progression-free (PFS) and overall survival (OS) between groups. Results Among 210 eligible patients, the median age was 53 years (range 30–88). The majority of patients were Caucasian (83.8%). All patients received adjuvant chemotherapy with 90% receiving carboplatin and paclitaxel. Thirty-eight (18.1%) patients received 3 cycles, and 172 (81.9%) patients received 6 cycles of adjuvant treatment. Recurrence rate was comparable between groups (18.4% vs. 27.3% for 3 vs. 6 cycles, p=0.4). There was no impact of 3 versus 6 cycles of chemotherapy on PFS (hazard ratio [HR] 1.4; 95% confidence interval [CI] 0.63–3.12, p=0.4) or OS (HR 1.65; 95% CI 0.59–4.65, p=0.3) on univariate analysis. There was no benefit to more chemotherapy in stratified analysis by stage nor on multivariate analysis adjusting for the impact of stage. Subgroup analysis of surgically staged patients also showed no difference in survival between 3 versus 6 cycles of chemotherapy. Conclusions Three cycles of platinum with or without taxane adjuvant chemotherapy were comparable to 6 cycles with respect to recurrence and survival in patients diagnosed with early stage ovarian clear cell carcinoma in this retrospective multi-institutional cohort.

Clear cell carcinoma of the ovary

“…[12] An exploratory analysis broken down by histology suggested that patients with HGSC histology benefit from 6 cycles of chemotherapy but OCCC histology does not. [13] A recent retrospective cohort confirmed this finding, [14] raising the question of the efficacy and optimal number of cycles of upfront chemotherapy for OCCC.…”

The possible existence of occult metastasis in patients with ovarian clear-cell carcinoma who underwent complete resection without any residual tumours

“…With regard to the number of chemotherapy cycles, Prendergast et al reported that analyzing 38 (18.1%) patients received 3 cycles, and 172 (81.9%) patients received 6 cycles of mainly carboplatin-paclitaxel chemotherapy, and recurrence was comparable between the groups (18.4 vs. 27.3% for 3 vs. 6 cycles, respectively, N.S.). There was no impact of 3 versus 6 cycles of chemotherapy on recurrence-free or overall survival on univariate analysis ( NS ) [ 9 ]. These observations demonstrated that the effect of postoperative chemotherapy in CCC patients is so limited that the control of the budding of “recurrence seeds” and subsequent proliferation is difficult.…”

Clear cell carcinoma of the ovary: a clinical and molecular perspective

“…94 A study of 210 patients showed that there was no impact of three versus six cycles of chemotherapy on overall survival in earlystage clear cell carcinoma. 95 Further studies of early-stage disease are required to determine which stages of disease benefit from chemotherapy and how many cycles of adjuvant chemotherapy are appropriate. At present, the Japanese Gynecologic Oncology Group (JGOG) is performing a randomized phase III trial to evaluate the necessity of adjuvant chemotherapy in stage I epithelial ovarian cancer (stage IA/IB clear cell carcinoma or grade 2/3 other histological type and stage IC1 with all grades and histological types) after comprehensive staging surgery (JGOG3020, UMIN000008481).…”