Impact of adjuvant chemotherapy and surgical staging in early-stage ovarian carcinoma: European Organisation for Research and Treatment of Cancer-Adjuvant ChemoTherapy in Ovarian Neoplasm trial

J Natl Cancer Inst. 2003 Jan 15;95(2):113-25.

Abstract

Background: All randomized trials of adjuvant chemotherapy for early-stage ovarian cancer have lacked the statistical power to show a difference in the effect on survival between adjuvant chemotherapy and no adjuvant chemotherapy. They have also not taken into account the adequacy of surgical staging. We performed a prospective unblinded, randomized phase III trial to test the efficacy of adjuvant chemotherapy in patients with early-stage ovarian cancer, with emphasis on the extent of surgical staging.

Methods: Between November 1990 and January 2000, 448 patients from 40 centers in nine European countries were randomly assigned to either adjuvant platinum-based chemotherapy (n = 224) or observation (n = 224) following surgery. Endpoints were overall survival and recurrence-free survival, and the analysis was on an intention-to-treat basis. The Kaplan-Meier method was used to perform time-to-event analysis, and the log-rank test was used to compare differences between treatment arms. Statistical tests were two-sided.

Results: After a median follow-up of 5.5 years, the difference in overall survival between the two trial arms was not statistically significant (hazard ratio [HR] = 0.69, 95% confidence interval [CI] = 0.44 to 1.08; P =.10). Recurrence-free survival, however, was statistically significantly improved in the adjuvant chemotherapy arm (HR = 0.63, 95% CI = 0.43 to 0.92; P =.02). Approximately one-third of patients (n = 151) had been optimally staged and two-thirds (n = 297) had not. Among patients in the observation arm, optimal staging was associated with a statistically significant improvement in overall and recurrence-free survival (HR = 2.31 [95% CI = 1.08 to 4.96]; P =.03 and HR = 1.82 [95% CI = 1.02 to 3.24] P =.04, respectively). No such association was observed in the chemotherapy arm. In the non-optimally staged patients, adjuvant chemotherapy was associated with statistically significant improvements in overall and recurrence-free survival (HR = 1.75 [95% CI = 1.04 to 2.95]; P =.03 and HR = 1.78 [95% CI = 1.15 to 2.77]; P =.009, respectively). In the optimally staged patients, no benefit of adjuvant chemotherapy was seen.

Conclusion: Adjuvant chemotherapy was associated with statistically significantly improved recurrence-free survival in patients with early-stage ovarian cancer. The benefit of adjuvant chemotherapy appeared to be limited to patients with non-optimal staging, i.e., patients with more risk of unappreciated residual disease.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / therapeutic use*
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Carboplatin / administration & dosage
  • Carcinoma / drug therapy*
  • Carcinoma / pathology*
  • Carcinoma / surgery
  • Chemotherapy, Adjuvant
  • Cisplatin / administration & dosage
  • Confidence Intervals
  • Disease-Free Survival
  • Europe
  • Female
  • Humans
  • International Cooperation
  • Middle Aged
  • Neoplasm Staging
  • Observation
  • Odds Ratio
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / pathology*
  • Ovarian Neoplasms / surgery
  • Prognosis
  • Risk Factors
  • Survival Analysis
  • Treatment Outcome

Substances

  • Antineoplastic Agents
  • Carboplatin
  • Cisplatin