1245 Association of KELIM score and Böhm’s chemotherapy response score with disease-free survival in patients with advanced ovarian cancer

Introduction/Background KELIM (CA-125 elimination rate constant K) and Böhm's chemotherapy response score (CRS) have recently been proposed for the assessment of response to neoadjuvant chemotherapy (NACT) in advanced ovarian cancer (OC). In fact, these two scoring systems could be used to guide clinicians in selecting the appropriate maintenance therapy in the first-line setting by measuring the biomarker's dynamic and histologic regression, respectively. Our primary aim is to investigate the association between KELIM and Böhm's score with disease-free survival (DFS). Methodology This retrospective cohort study includes patients with FIGO stage IIIC-IV high-grade serous OC who underwent interval debulking surgery (IDS) at the European Institute of Oncology between 03.2018–03.2023, and for which both KELIM and Böhm's scores were available. KELIM score can be calculated when at least three CA125 values are measured within the first 100 days from the start of NACT, categorizing patients as either unfavorable(Results In total, 60 patients meeting inclusion criteria were identified, 41(68.3%) with unfavorable and 19(31.7%) favorable KELIM, while 25(41.7%) were CRS1, 27(45.0%) CRS2, and 8(13.3%) CRS3. All 4(100%) platinum-resistant patients had unfavorable KELIM. Favorable KELIM showed a longer DFS than unfavorable KELIM median DFS 26.7 vs. 13.7 months; p=0.003 (Figure 1). At univariable analysis, age, residual tumor, Böhm's and KELIM scores were associated with DFS. In the multivariable model, age at diagnosis, Böhm and KELIM remained independent predictors of DFS (Table 1). Conclusion These results confirm the independent association of both KELIM and Böhm with DFS in patients with advanced OC undergoing NACT followed by IDS, further supporting their role in selecting a personalized maintenance therapy. Disclosures No disclosures.