title: Is there a high-risk subgroup of stage I epithelial ovarian cancer that is most likely to benefit from 6 versus 3 cycles of adjuvant chemotherapy?
abstract: OBJECTIVE
  Despite results from Gynecologic Oncology Group (GOG) 157 showing no statistically significant survival differences in patients treated with 3 versus 6 cycles of carboplatin and paclitaxel, further analysis of GOG 157 data suggested that certain early-stage epithelial ovarian cancers (EOCs) might benefit from extended chemotherapy. We sought to determine those stage I EOC cases at highest risk of failing 3 cycles of therapy.
  
  
  METHODS
  All patients with surgical International Federation of Gynecology and Obstetrics stage I EOC operated on at the Mayo Clinic and The Ohio State University between January 1991 and December 2007 were identified through retrospective chart review. A cohort of patients who received 6 cycles of adjuvant carboplatin and paclitaxel chemotherapy was compared with a cohort of patients who received 3 cycles. Disease-free survival and disease-specific survival were primary outcomes analyzed.
  
  
  RESULTS
  There were 107 patients who received either 3 or 6 cycles of adjuvant carboplatin and paclitaxel. Among all stage I EOCs, the number of cycles did not influence disease-free survival or disease-specific survival. The highest recurrence rate (7 [46.7%] of 15 cases) was among stage IC cases with fixed tumors and positive cytology and/or surface involvement. Among this cohort, 6 (66.7%) of the 9 patients who received 3 cycles recurred, whereas only 1 (16.7%) of the 6 patients who received 6 cycles recurred (hazard ratio, 5.97; 95% confidence interval [CI], 0.98-114.46; P = 0.05, Cox proportional hazards regression model) for an odds ratio of 3.94. The absolute risk reduction for 6 cycles in this highest risk cohort was 50%.
  
  
  CONCLUSIONS
  Patients with stage IC cancer and with fixed tumors and positive cytology and/or tumor surface involvement appear to have a higher risk of recurrence after 3 cycles (compared with 6) of platinum-based chemotherapy. The clinical behavior of this highest risk cohort implies a more aggressive tumor biology, and further understanding of such stage I EOCs is warranted.
authors.affiliation: Division of Gynecologic Surgery, Mayo Clinic, Rochester, MN 55905, USA. bakkum.jamie@mayo.edu
authors.forename: Jamie N
authors.initials: JN
authors.lastname: Bakkum-Gamez
authors.forename: Debra L
authors.initials: DL
authors.lastname: Richardson
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Seamon
authors.forename: Giovanni D
authors.initials: GD
authors.lastname: Aletti
authors.forename: Cecelia A
authors.initials: CA
authors.lastname: Powless
authors.forename: Gary L
authors.initials: GL
authors.lastname: Keeney
authors.forename: David M
authors.initials: DM
authors.lastname: O'Malley
authors.forename: William A
authors.initials: WA
authors.lastname: Cliby
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D017024:Chemotherapy, Adjuvant; D018284:Cystadenocarcinoma, Serous / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D017239:Paclitaxel / Q000008:administration & dosage; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D016190:Carboplatin; D017239:Paclitaxel