Predictors and Cumulative Frequency of Hepatocellular Carcinoma in High and Intermediate LI-RADS Lesions: A Cohort Study from a Canadian Academic Institution

Abstract

BackgroundThe frequency and predictors of hepatocellular carcinoma (HCC) within each liver imaging reporting and data system (LI-RADS) category remains unclear. We sought to estimate the cumulative frequency of HCC in LI-RADS observations of high/intermediate category and identify clinical/radiographic features associated with HCC.MethodsOur diagnostic imaging database was searched for computed tomography/magnetic resonance imaging reports of patients with evidence of cirrhosis and liver observations. LI-RADS categories were determined by imaging review, while demographic and clinical outcomes were assigned by chart review. A composite outcome of clinical/radiographic confirmation of HCC was used. We used multivariable analysis to identify features associated with HCC, and competing risks regression to estimate the cumulative frequency of HCC in each category.ResultsOur search returned 95 patients with 137 observations (LR2\u2009=\u20094, LR3\u2009=\u200953, LR4\u2009=\u200937, and LR5\u2009=\u200943). On multivariable analysis, increasing age (hazard ratio [HR] 1.76 per 10\xa0years, p\u2009=\u20090.049), washout (HR 5.34, p\u2009<\u20090.002), and increasing size (size\u2009<\u200910\xa0mm reference, 10–20\xa0mm, HR 3.93, p\u2009=\u20090.014; size\u2009>\u200920\xa0mm, HR 21.69, p\u2009<\u20090.001) were associated with HCC. Median time to diagnosis was 6.13\xa0months (interquartile range [IQR] 4.6–13.1), 4.7\xa0months (IQR 2.5–14.5), and 3.6\xa0months (IQR 1.9–6.6) for LR3, 4, and 5 category observations, respectively. The cumulative frequency of HCC was 59.8% in LR3, 84.62% in LR4, and 99.84% in LR5, at last follow-up.ConclusionThe frequency of HCC within each LI-RADS category reflects the intended purpose, intermediate probability for LR3, probable HCC for LR4, and definite HCC for LR5.