title: The significance of combination chemotherapy in epithelial ovarian cancer.
abstract: OBJECTIVE
  Since the publication of International Collaborative Ovarian Neoplasm 3, various practice patterns have evolved with respect to practice patterns and survival among women with epithelial ovarian cancer in British Columbia, Canada. The objectives of this study were to evaluate different strategies for first-line chemotherapy in ovarian cancer and to determine their effect on survival at a population level.
  
  
  METHODS
  This was a retrospective population-based cohort study of 854 women with epithelial ovarian cancer in British Columbia from 2005 to 2008. Details were ascertained on stage, grade, histotype, performance status, surgeon type, extent of debulking, first-line chemotherapy including type and number of cycles, and cause and date of death. A Cox regression model was used to evaluate the association of covariates on overall survival.
  
  
  RESULTS
  Of the 817 women eligible for chemotherapy, 729 (89.2%) received treatment, including 106 (14.5%) women who received single-agent carboplatin and 623 (85.5%) women who received combination platinum-based chemotherapy. Chemotherapy was evaluated as a time-varying covariate. Median numbers of single-agent carboplatin and combination chemotherapy cycles were 5 (range, 1-11) and 6 (range, 1-12), respectively. After adjustment for demographic, disease, and treatment factors, the covariates significantly associated with survival were stage, performance status, extent of debulking, and chemotherapy type. Single-agent carboplatin had a mortality hazards ratio of 5.15 (95% confidence interval, 2.39-11.11) relative to combination chemotherapy.
  
  
  CONCLUSIONS
  In this population-based study, first-line platinum-based combination chemotherapy was associated with improved survival compared with single-agent carboplatin after adjustment for covariates in ovarian cancer. Higher rates of combination chemotherapy may improve outcomes at a population level.
authors.affiliation: *Division of Gynecologic Oncology, University of British Columbia; †Cancer Surveillance and Outcomes, Population Oncology, BC Cancer Agency; ‡Department of Obstetrics and Gynecology, University of British Columbia; and §Cheryl Brown Ovarian Cancer Outcomes Unit, BC Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Janice S
authors.initials: JS
authors.lastname: Kwon
authors.forename: Colleen
authors.initials: C
authors.lastname: McGahan
authors.forename: Ulrike
authors.initials: U
authors.lastname: Dehaeck
authors.forename: Jennifer
authors.initials: J
authors.lastname: Santos
authors.forename: Kenneth
authors.initials: K
authors.lastname: Swenerton
authors.forename: Mark S
authors.initials: MS
authors.lastname: Carey
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols; D001955:British Columbia / Q000453:epidemiology; D016190:Carboplatin / Q000008:administration & dosage*; D002277:Carcinoma / Q000188:drug therapy* / Q000401:mortality; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000401:mortality; D012189:Retrospective Studies
chemical_list: D000970:Antineoplastic Agents; D016190:Carboplatin