Abstract
Background: Three subphenotypes were identified for unresectable hepatocellular carcinoma (uHCC) after frontline transarterial chemoembolization (TACE). This study aimed to develop an individual smHAP-Ⅱ nomogram for uHCC patients after TACE. Methods: Between January 2007 to December 2016, 1517 uHCC patients undergoing TACE were included from four hospitals in China (derivation cohort: 597 cases; validation cohort: 920 cases). Multivariable Cox proportion regression analysis was used to develop a nomogram, incorporating postoperative subphenotypes (Phenotype 1, 2, 3) and HAP score (Score 0 to 4). The model was validated by a 1000-time bootstrap resampling procedure. The performance of the model was compared with existing ones by Harrell's C-index and Area Under Curve (AUC). Results: Postoperative subphenotypes modified the HAP score (smHAP-Ⅱ nomogram) was developed and validated, with the Harrell's C-index of the nomogram was 0.679 (SD: 0.029) for the derivation cohort and 0.727(SD:0.029) for the external cohort. The area under curves of the nomogram for 1-, 3-, and 5-year OS were 0.750, 0.710, and 0.732 for the derivation cohort, respectively (0.789, 0.762, and 0.715 for the external cohort). In the calibration curves stratified by treatment after TACE, the lines for re-TACE and stop-TACE cross at 0.23, indicating that patients with a 3-year predicted survival >23% would not benefit from TACE. Conclusions: The addition of postoperative subphenotypes significantly improved the prognostic performance. The smHAP-Ⅱ nomogram can be used for accurate prognostication and selection of optimal candidates for TACE, with the value to guide sequential treatment strategy.