79O Clinical performance of Immunoscore® in early colon cancer in the Asian population

(eng) Background Immunoscore® is an in vitro diagnostic test predicting the risk of relapse in early-stage Colon Cancer (CC), by measuring the host immune response at the tumor site. This risk-assessment tool provides independent and superior prognostic value than the usual risk parameters and is intended to be used as an adjunct to the TNM classification for clinical decision. In the present study, we investigated Immunoscore® clinical performance in the Asian population from the international SITC-led validation study (Pagès et al. The Lancet 2018). Methods Out of the 2681 eligible stage I-III patients of the international Immunoscore® study, 423 were collected from 4 expert centers in Asia including Japan (n=330), China (n=35), and India (n=58). Patients were classified by Immunoscore® based on pre-defined cutoffs, either in 5 (IS 0-4) or 2 categories: IS Low (IS 0-1) and IS High (IS 2-4). Time to recurrence (TTR) was compared between Immunoscore® categories. Results Immunoscore® Low and High were observed in 37% (n=158) and 63% (n=265) of the Asian cohort, respectively. Immunoscore® was positively and significantly correlated with TTR. After 5 years, 86.9% (95% CI 82.7-91.4), and 77% (95% CI 70,5-84,1) of Immunoscore -High and -Low patients respectively were event free (HR =0.52; 95% CI 0.32-0.86; p=0.0085). When adjusting the model with Immunoscore®, age, gender, T-stage, N-stage, sidedness and MSI, and when stratified by center, Immunoscore® remained a significant parameter (HR=0.45; 95% CI 0.22-0.91; p=0.027). When stratified into 5 Immunoscore® categories, TTR rates at 5 years were 100%, 96%, 84%, 80%, and 73.5% for IS4, IS3, IS2, IS1, IS0, respectively. These results were similar to those found in European and North American patients. Conclusions Immunoscore® is a strong prognostic indicator of the risk of recurrence in stage I-III CC patients who receive standard of care treatment in real-life clinical practice in Asia. This first standardized immune-based assay risk assessment tool can be used reliably to guide clinical decision according to each patient information.