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.