MRI-based prediction of very early recurrence within 1 year after resection of HCC: An international cohort study

BACKGROUND & AIMS: Very early recurrence (within 1 year after resection) of hepatocellular carcinoma (HCC) indicates aggressive tumor biology and poor prognosis; however, non-invasive prediction tools remain scarce. This study aimed to develop and validate MRI-based models for predicting very early recurrence and to explore their biological underpinnings. METHODS: This international, multicenter cohort study retrospectively included 1,811 consecutive patients who underwent curative-intent resection for a single BCLC 0/A HCC and preoperative contrast-enhanced MRI or CT at 14 tertiary care hospitals in China, South Korea, Singapore, France, and the USA, as well as 40 eligible patients from the TCGA-LIHC dataset. To predict 1-year recurrence-free survival (RFS), MRI for Very Early Recurrence Prediction (MERP) models were developed using either preoperative variables alone (MERP-pre) or a combination of pre- and postoperative variables (MERP-post) in the derivation cohort (n = 628). The models were externally validated in Eastern (n = 775) and Western (n = 178) test cohorts and further evaluated in a CT test cohort (n = 230). Biological correlates were investigated using whole-exome and RNA sequencing. RESULTS: MERP-pre incorporated alpha-fetoprotein, tumor size, portal venous phase peritumoral hypoenhancement, and intratumoral blood products, whereas MERP-post replaced tumor size with microvascular invasion (MVI). Both models outperformed major staging systems and the IMbrave050 criteria across all test cohorts (C-index, 0.685-0.790 vs. 0.524-0.682; p values,