Predictors for Early Liver Cancer Survival After Ablation and Surgical Resection: A Surveillance, Epidemiology, and End Results Program-Medicare Study

To identify independent predictors of all-cause and cancer-specific mortality following ablation (AB) or surgical resection (SR) for small HCCs, after adjusting for key confounders.Using SEER-Medicare, HCCs less than 5 cm treated with AB or SR in 2009-2016 (N=956) were identified. Univariate and multivariable Cox regression models for all-cause and cancer-specific mortality were performed including demographics, clinical factors (tumor size, medical comorbidities, and liver disease factors), social determinants of health and treatment characteristics. We also determined the most influential predictors of survival using a random forest analysis.Larger tumor size (3-5 cm) is predictive of all-cause (HR 1.31, p-value 0.002) and cancer-specific mortality (HR 1.59, p-value <0.001). Furthermore, chronic kidney disease is predictive of all-cause mortality (HR 1.43, p-value 0.013), though it is not predictive of cancer-specific death. Multiple liver disease factors are predictive of all-cause and cancer-specific mortality including portal hypertension and esophageal varices (HRs >1, p-values <0.05). Though Asian race is protective in univariate models, in fully adjusted, multivariable models, Asian race is not a significant protective factor. Likewise, other social determinants of health are not significantly predictive of all-cause or cancer-specific mortality. Finally, treatment with SR, in later procedure years or at high volume centers is protective for all-cause and cancer-specific mortality. In machine learning models, year procedure performed, ascites, portal hypertension and treatment choice were the most influential factors.Treatment characteristics, liver disease factors and tumor size are more important predictors of all-cause and cancer-specific death than social determinants of health for small HCCs.