Development and Validation of a Clinicopathological-Based Nomogram to Predict the Survival Outcome of Patients with Recurrent Hepatocellular Carcinoma After Hepatectomy Who Underwent Microwave Ablation

Chunhou Qi,1 Shankai Li,1 Lei Zhang2 1Department of Interventional Medicine, Linyi City Central Hospital, Yishui, Shandong, People’s Republic of China; 2Department of Interventional Radiology, Shandong Medical Imaging Research Institute, Affiliated to Shandong University, Jinan, Shandong, People’s Republic of ChinaCorrespondence: Lei ZhangDepartment of Interventional Radiology, Shandong Medical Imaging Research Institute, Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, People’s Republic of ChinaTel +86-531-68776767Fax +86-531-87938550Email zhanglei0422@yeah.netAim: To develop and validate a nomogram for predicting the overall survival (OS) in patients with recurrent hepatocellular carcinoma (HCC) after hepatectomy who underwent microwave ablation (MWA).Methods: The training cohort included 299 patients with recurrent HCCs after hepatectomy who met the Milan criteria and received MWA from April 2007 to December 2017. Baseline characteristics were collected to identify risk factors for the determination of death after MWA. A multivariate Cox proportional hazards model based on significant risk factors was used to develop the nomogram, which was then assessed for its predictive accuracy using Harrell’s C-index and the area under the curve (AUC). The nomogram was validated by internal (n = 240) and external cohorts (n = 205) from another hospital.Results: After a median follow-up of 32.3 months, 38.8% (116/299) of patients had died. Multivariate Cox proportional hazards analyses showed that comorbid disease, early recurrence, and albumin-bilirubin (ALBI) grades 2– 3 were independent prognostic factors for poor OS. This nomogram accurately stratified patients into subgroups with low or high risk. The 1-, 3- and 5-year OS rates in the low-risk subgroup were 99.4%, 97.2%, and 86.1%, respectively, and they were 92.8%, 70.3%, and 45.8% in the high-risk subgroup (P < 0.001). The nomogram predicted OS in the training cohort with a C-index score of 0.801 (95% CI 0.761– 0.841). The nomogram was validated by internal and external cohorts, with C-index scores of 0.792 (95% CI 0.738– 0.846) and 0.744 (95% CI 0.703– 0.785), respectively.Conclusion: The nomogram provides individualized risk estimates for long-term OS for patients with recurrent HCC after hepatectomy who underwent MWA.Keywords: recurrent hepatocellular carcinoma, microwave ablation, overall survival, nomogram, hepatectomy