Duration of second or greater complete clinical remission in ovarian cancer: Exploring potential endpoints for clinical trials

Abstract

Objective. To explore benchmarks for future consolidation strategies, we evaluated a strictly defined (normal CA-125 and normal CT) second-complete-remission (CR) ovarian cancer population for 1) the median progression-free survival (PFS), 2) the frequency with which second remission exceeds first, and 3) the proportion of patients in remission at given time points. Methods. Retrospective sampling was carried out at Memorial Sloan-Kettering (10/1993–12/2000) and the Royal Marsden Hospital (1/1995–4/2003) for the following: histological confirmation and elevated CA-125 at diagnosis; primary surgery; first-and second-line platinum-based chemotherapy with CR; and no maintenance therapy. Results. In 35 patients 1) the duration of first PFS was 17.8 months (95% CI, 13.2–24.5 months) and second PFS was 10.8 months (95% CI, 9.6–12.2 months); 2) the number of patients with second response longer than first was 3/35 (9%); 3) the proportion of patients remaining in second complete remission was 100% (3 months), 100% (6 months), 83% (9 months), 34% (12 months), 23% (15 months) and 8.6% (18 months), respectively. Conclusion. 1) The median PFS from second complete remission is short. 2) A second response is rarely longer than the first even in this second CR population. 3) The number of patients with a second response longer than the first, or the proportion of patients remaining in complete remission at given time points could be evaluated as an outcome measure in future studies.