Nomograms to predict survival outcomes after microwave ablation in elderly patients (>65 years old) with early-stage hepatocellular carcinoma

Abstract

Objectives To develop and validate the nomograms to predict survival outcomes after microwave ablation (MWA) in elderly patients(>65 years old) with early-stage hepatocellular carcinoma (EHCC). Methods This retrospective study was approved by the institutional review board. A total of 265 EHCC patients (76 females, 189 males; average age 71.4 years ± 5.4 [standard deviation]) with 345 nodules subsequently underwent MWA from April 2006 to October 2019. Baseline characteristics were collected to identify the risk factors for the determination of survival outcomes after MWA. The nomograms were based on prognostic factors for overall survival (OS) and recurrence-free survival (RFS) from the multivariate Cox proportional hazards model and validated in external cohorts from another two institutions (n = 130). The nomograms were assessed for their predictive accuracy using Harrell’s concordance index (C-index). Results After a median follow-up time of 28.6 months, 29.8% (79/265) of the patients died, and 54.3% (144/265) of the patients experienced recurrence in the training set. The OS nomogram was developed based on the hepatitis B virus (HBV) presence, α-fetoprotein (AFP), and albumin, with a C-index of 0.757 (95% confidence interval [CI]: 0.645, 0.789).The scores of the nomogram ranged from 0 to 24. The RFS nomogram was developed based on tumor number, abutting major vessels and platelets, with a C-index of 0.733 (CI: 0.672, 0.774). The likelihood of 3- and 5-year OS and RFS were consistent between clinical observations and nomogram predictions in external cohorts. Conclusions The nomogram models can be useful in determining the risk of OS and RFS in elderly patients with EHCC after MWA, which can guide individual patient management. Key points MWA is an effective and feasible treatment for elderly patients with EHCC and can improve survival outcomes. A calibrated and objective nomogram model for the prediction of survival outcomes in elderly patients (>65 years old) may guide patient selection and MWA treatment. Older age was not deemed to be a risk factor for survival outcomes when the elderly patients with EHCC underwent MWA.