Randomized phase III trial of three versus six cycles of adjuvant carboplatin and paclitaxel in early stage epithelial ovarian carcinoma: a Gynecologic Oncology Group study.

Objective: Compared to 3 cycles, to determine if 6 cycles of adjuvant carboplatin (C) and paclitaxel (P) significantly lower the rate of recurrence in surgically staged patients with stage IA grade 3, IB grade 3, clear cell, IC, and completely resected stage II epithelial ovarian cancer (EOC); and to compare toxicities.
Methods: Postoperatively, randomization was to either 3 or 6 cycles of chemotherapy consisting of P (175 mg/m2 over 3 h) and C (7.5 AUC over 30 min) every 21 days. Recurrence was any clinical or radiological evidence of new tumor.
Results: Of 457 patients, 427 (93%) were histologically and medically eligible. While thorough surgical staging was required, it was incomplete or inadequately documented in 29% of otherwise eligible patients. Median age was 55.5 years; 69% of patients had stage I disease. Median follow-up is 6.8 years for 344 women alive at last contact. Grade 3 or 4 neurotoxicity occurred in 4/211 (2%) and 24/212 (11%) treated patients on the 3- and 6-cycle regimens, respectively (p<0.01); 6 cycles also caused significantly more severe anemia and granulocytopenia. The recurrence rate for 6 cycles was 24% lower (hazard ratio [HR]: 0.761; 95% confidence interval [CI]: 0.51-1.13, p=0.18), and the estimated probability of recurrence within 5 years was 20.1% (6 cycles) versus 25.4% (3 cycles). The overall death rate was similar for these regimens (HR: 1.02; 95% CI: 0.662-1.57).
Conclusions: Compared to 3 cycles, 6 cycles of C and P do not significantly alter the recurrence rate in high risk early stage EOC but are associated with more toxicity.