The evolution process of risk factor and recurrence pattern for solitary 3–5 cm HCC after initial treatment

High recurrence is a notorious feature of hepatocellular carcinoma (HCC) and also the major reason for HCC-related death, so identifying risk factors on tumor recurrence is crucial for building prediction model, selecting treatment method and providing follow-up recommendation. The aim is to explore the evolution process of risk factor and recurrence pattern for solitary 3–5 cm HCC after initial treatment. Clinical information of patients underwent laparoscopic hepatectomy (LH) or microwave ablation (MWA) with solitary 3–5 cm HCC were collected to identify risk factor on recurrence by Cox proportional hazard model. Then, Landmark test was used to analyze the duration time and calculate the hazard ratio (HR) of each factor from 6th to 36th month after initial treatment. Tumor recurrence pattern was recorded and classified into three types: local recurrence (LR), intrahepatic proximal recurrence (PR), and intrahepatic distal recurrence (DR). From January 2010 to October 2019, 1207 patients from 12 hospitals were included with a 38.7-month median follow-up. Multivariate analysis showed: male, cirrhosis, elevated alpha-fetoprotein (AFP) and MWA were risk factors for recurrence. Landmark test and correlation analysis show that: elevated-AFP was the very short-term risk factor ( p < 0.05, HR > 1) with a 12 months duration time, and most LR occurred in this period (75.0%, 30/40); In short term follow up (within 24 months), MWA was the most significant risk factor ( p < 0.05, HR > 1), and a higher proportion of PR was detected than DR in this period (55.3% vs. 33.3%); male and cirrhosis were the long-term risk factor on recurrence ( p < 0.05, HR > 1), and when the short-term and very short-term risk factors failed, the proportion of PR and DR become comparable (48.8% vs. 46.3%). The influence of factors on tumor recurrence can evolve over time and recurrence pattern also changed with the risk factor evolution.