ICON1 Study

International Collaborative Ovarian Neoplasm Trial 1: A Randomized Trial of Adjuvant Chemotherapy in Women With Early-Stage Ovarian Cancer (ICON1)

Disease site


Publication month/year

January 2003

Study question

Can adjuvant chemotherapy improve overall survival and prolong recurrence-free survival in women with early-stage epithelial ovarian cancer?

Type of study

Randomised controlled trial (RCT)

Interventions compared


Experimental arm (Intervention)
  • Adjuvant chemotherapy immediately following surgery (n=241)
  • Single agent Carboplatin or CAP (AUC every 3 weeks)
Control arm
  • No adjuvant chemotherapy until clinically indicated (n = 236)
Primary outcome
  • Overall survival (OS)
Secondary outcome
  • Recurrence Free Survival (RFS)
Inclusion criteria
  • Confirmed ovarian carcinoma of epithelial origin
  • The clinician was uncertain as to whether to offer immediate adjuvant chemotherapy
  • All visible tumour removed during surgery (Hysterectomy & Bilateral Salpingoopherectomy & Omenetectomy)
Exclusion criteria
  • The patient was not fit to receive chemotherapy
  • Patient had previous malignant disease (except nonmelanoma skin cancer)
  • Patient had previous radiation therapy or chemotherapy
Chemotherapy Group No Chemotherapy Group
Randomised(n) 241 236
Received treatment(n) 197 230
Alive no recurrence (n, %) 185(77%) 167(67%)
Alive with recurrence (n,%) 14(6%) 18 (8%)
Dead without recurrence (n,%) 8(3%) 18(8%)
Dead after recurrence (n,%) 33(14%) 42(18%)
Overall Survival(%) 79% 70%
Recurrence free survival @ 5ys(%) 73% 62%
  • All patients with early-stage ovarian cancer should be considered for platinum-based adjuvant chemotherapy after removal of all visible tumour
  • Single-agent Carboplatin should be considered as the treatment of choice
Study limitations
  • Did not take in consideration¬†pathological stage or tumour histology subtype/grade
  • Recruitment significantly less than what was planned (Planned=2000, Actual= 477)
Additional resources
Reviewer name