Article Text
Abstract
Introduction/Background Older patients (pts) with ovarian cancer have a poorer survival, classically related to suboptimal treatment or excessive toxicities; however histological aggressivity and chemoresistance may contribute to this worse outcome. CA-125 elimination rate constant K (KELIM) was shown to be a robust marker of intrinsic chemosensitivity either in adjuvant or neoadjuvant settings. EWOC-1 trial (NCT02001272) was designed to evaluate the feasibility of three treatment regimens in vulnerable pts aged ≥70 years in first line; pts treated with carboplatin monotherapy (C) had a 2.79-fold higher risk of death compared to carboplatin-paclitaxel (CP). An ancillary analysis of EWOC-1 was designed to evaluate the differential chemosensitivity in the 3 treatment arms using KELIM.
Methodology KELIM calculation was performed according to You et al. (www.biomarker-kinetics.org™/CA125-neo) on EWOC-1 trial database of 120 pts (40 in each arm: standard CP (arm A); C (arm B); 3w/4 weekly CP (arm C)).
Results KELIM was evaluable for 58 pts (A: 18; B: 22; C: 18), its median [IQR] was 0.76 (0.59; 0.90) in the total population, significantly associated with treatment arms: A: 0.99 [0.71; 1.11]; B: 0.56 [0.32; 0.77]; C: 0.77 [0.50; 0.90], p=0.008; pairwise comparison arm A vs B, p=0.001. Only 15 pts (25.9%) had a favorable (≥1) KELIM, associated with a significant increase in overall survival (HR: 0.240; 95%CI: 0.089–0.645; p=0.002).
Conclusion KELIM values were globally unfavorable in this older population. Chemosensitivity was highly dependent on the treatment regimen, with a median KELIM comparable in the standard carboplatin-paclitaxel arm (A) to previously published data on younger patients. These data strengthen the need to avoid under-treatment in the older population. KELIMTM may be considered in older pts as both a marker of intrinsic- (tumor-related) and extrinsic-(treatment-related) chemosensitivity.