599PA VALIDATION OF CURRENT PROGNOSTIC SCORES IN METASTATIC COLORECTAL CANCER (MCRC) AND A NEW PROGNOSTIC SCORE (A GEMCAD STUDY)

Abstract Aim: Background: The two main prognostic scores for mCRC (Kohne and GERCOR) do not account for resectability of liver-only metastasis (LiM) and thus are limited as treatment guidance. We propose a classification of patients based on LiM resectability, performance status (PS) and lactate dehydrogenase (LDH) levels and compare its discrimination capacity against Kohne and GERCOR scores. Methods: We analyzed 395 patients treated with first-line oxaliplatin-based regimes with or without monoclonal antibodies. Patients were classified as stage 1 if LiM were considered resectable ( 1.5 ULN. This score, Kohne, and GERCOR scores were tested for discrimination using Harrel's C index (HCI, higher is better) and calibration using Akaike information criterion (AIC, smaller is better) of progression-free survival (PFS) and overall survival (OS). Results: Group 1Group 2Group 3GEMCADN78206111PFS HR (95% CI)1 (Reference)2.07 (1.54-2.78)2.98 (2.15-4.13)PFS HCI (95% CI)0.66 (0.60-0.73)PFS AIC3496.2OS HR (95% CI)1 (Reference)2.14 (1.52-3.00)3.68 (2.55-5.32)OS HCI (95% CI)0.68 (0.62-0.73)OS AIC2903.7KohneN15920531PFS HR (95% CI)1 (Reference)1.55 (1.23-1.93)2.86 (1.89-4.31)PFS HCI (95% CI)0.62 (0.56-0.68)PFS AIC3515.7OS HR (95% CI)1 (Reference)1.63 (1.27-2.10)4.57 (2.93-7.13)OS HCI (95% CI)0.65 (0.60-0.71)OS AIC2915.4GERCORN116153126PFS HR (95% CI)1 (Reference)1.40 (1.08-1.82)2.04 (1.55-2.68)PFS HCI (95% CI)0.60 (0.54-0.66)AIC3517.7OS HR (95% CI)1 (Reference)2.19 (1.62-2.96)3.21 (2.34-4.40)OS HCI (95% CI)0.66 (0.62-0.71)OS AIC2898.4 Conclusions: Conclusions. GEMCAD score performs as well, if not better, than Kohne and GERCOR scores and allows treatment guidance. Disclosure: All authors have declared no conflicts of interest.