Development of a Prognostic Nomogram for Cancer-Specific Survival in Hepatoid Carcinoma: Insights from a Comprehensive SEER-Based Population Analysis

Abstract Background Hepatoid adenocarcinoma (HAC) is a poorly differentiated extrahepatic tumor that can produce alpha-fetoprotein (AFP). The prognostic factors of HAC have not been fully stated in the literature. Therefore, we present a novel nomogram to predict the cancer-specific survival (CSS) of patients with HAC. Methods In total, 265 cases with HAC were extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2004–2015. A prognostic nomogram was produced using the discovered risk factors and a Cox proportional hazard regression model. The nomogram's predictive ability was assessed by utilizing the concordance index (c-index), calibration curve, and receiver operating characteristic (ROC). Results Multivariate Cox regression showed that metastasis at the liver, surgery, and chemotherapy were independently correlated with CSS. A nomogram was developed using these factors, with a c-index of 0.71 (95% CI 0.71–0.96). Furthermore, calibration curves demonstrated concordance between the predicted survival probability from the nomogram and the observed survival probability. The areas under the curve (AUC) for 1-year, 3-year, and 5-year survival were 0.80, 0.82, and 0.88, respectively. Conclusion Our study successfully formulated a prognostic nomogram that offers promising predictions for the 1-, 3-, and 5-year Cancer-Specific Survival (CSS) of patients with HAC. This nomogram holds potential for practical use in guiding treatment decisions and designing clinical trials.