A Novel Prognostic Tool in Western and Eastern Biliary Tract Cancer Patients Treated in First-line Setting: the ECSIPOT Index

Background and Aim The need to estimate prognosis of advanced BTC (aBTC) patients treated with first-line chemotherapy is compelling. The aim of the study is to evaluate the ECSIPOT (psECogSIiPnigOT) index, influenced by PECS (PsECogSii) index, prognostic nutritional index (PNI), and GOT. Methods This international study was conducted on a training cohort of 126 patients and in three validation cohorts, both European and Korean. ECSIPOT index formula: (PECS:0 = 1 point; PECS:1 = 1.4 points; PECS:2 = 3.2 points) + (PNI > 36.7 = 1 point; PNI < 36.7 = 2 points) + (GOT < 100 = 1 point; GOT > 100 = 2 points). Event-time distributions were estimated using the Kaplan-Meier method, and survival curves were compared using the log-rank test. Results In the training cohort, mOS was 12.9, 6.3, and 2.8 months for patients with ECSIPOT-0, ECSIPOT-1, and ECSIPOT-2, respectively (ECSIPOT-0: HR 1; ECSIPOT-1: HR 2.11; ECSIPOT-2: HR 4.93; p < 0.0001). In the first validation cohort, mOS was 11.5, 7.3, and 3.3 months for ECSIPOT-0, ECSIPOT-1, and ECSIPOT-2, respectively (ECSIPOT-0: HR 1; ECSIPOT-1: HR 1.74; ECSIPOT-2: HR 3.41; p < 0.0001). In the second validation cohort, mOS was 25.2, 12.5, and 3.0 months for ECSIPOT-0, ECSIPOT-1, and ECSIPOT-2, respectively (ECSIPOT-0: HR = 1; ECSIPOT-1: HR 2.33; ECSIPOT-2: HR 8.46; p < 0.0001). In the third validation cohort, mOS was 11.8, 8.1, and 4.6 months for ECSIPOT-0, ECSIPOT-1, and ECSIPOT-2, respectively (ECSIPOT-0: HR = 1; ECSIPOT-1: HR 1.47; ECSIPOT-2: HR 3.17; p < 0.0001). Multivariate analysis in all cohorts confirmed the ECSIPOT index as an independent prognostic factor for OS. Conclusion The easy assessment and good risk-stratification performance make the ECSIPOT index a promising tool to comprehensively estimate the prognosis of aBTC patients.