A risk prediction model for hepatocellular carcinoma in non-alcoholic fatty liver disease without cirrhosis: HCC prediction for non-cirrhotic NAFLD.

BACKGROUND & AIMS: Although non-alcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC), HCC risk in non-cirrhotic NAFLD received little attention. We aimed to develop and validate an HCC risk prediction model for non-cirrhotic NAFLD. METHODS: A nationwide cohort of non-cirrhotic NAFLD patients in Korea was recruited to develop a risk prediction model and validate it internally (n = 409 088). A model using a simplified point system was developed by Cox proportional hazard model. K-fold cross-validation assessed the accuracy, discrimination and calibration. The model was validated externally using a hospital cohort from Asan Medical Center (n = 8721). RESULTS: An 11-point HCC risk prediction model for non-cirrhotic NAFLD was developed using six independent factors of age, sex, diabetes, obesity, serum alanine aminotransferase level and gamma-glutamyl transferase level (c-index 0.75). The average area under receiver operating curves (AUROCs) of the model was 0.72 at 5 years and 0.75 at 10 years. In the external validation cohort, the AUROCs were 0.79 [95% confidence interval [CI], 0.59-0.95] at 5 years and 0.84 (95% CI, 0.73-0.94) at 10 years. The calibration plots showed the expected risks corresponded well with the observed risks. Risk stratification categorized patients into the low (score 0-6), moderate (7, 8) and high (9-11; estimated incidence rate >0.2%/year) risk groups. CONCLUSIONS: A novel HCC risk prediction model for non-cirrhotic NAFLD patients was developed and validated with fair performance. The model is expected to serve as a simple and reliable tool to assess HCC risk and assist precision screening of HCC.

Metabolic dysfunction-associated steatotic liver disease and MetALD increases the risk of liver cancer and gastrointestinal cancer: A nationwide cohort study.

BACKGROUND: The new nomenclature of metabolic dysfunction-associated steatotic liver disease (MASLD) substituting nonalcoholic fatty liver disease was proposed along with a new category of MASLD with increased alcohol intake (MetALD). AIMS: We aimed to explore the cancer risk by MASLD and MetALD. METHODS: This nationwide cohort study included 3,596,709 participants who underwent a health check-up in 2011 in South Korea. Steatotic liver disease (SLD) was defined as a fatty liver index ≥30. Participants were categorized into four exclusive groups: MASLD, MetALD, other combination aetiology and no SLD. The subdistribution hazard ratio (SHR) was calculated using the Fine-Gray model after adjusting other variables. RESULTS: During the 33.9 million person-years of follow-up, 285,845 participants (7.9%) developed cancers. Compared with no SLD, MASLD, MetALD and other combination aetiology had an increased risk of all cancer. Liver cancer risk escalated from no SLD to MASLD (SHR, 1.16; 95% CI, 1.12-1.21), MetALD (SHR, 2.06; 95% CI, 1.92-2.20) and other combination aetiology (SHR, 8.16; 95% CI, 7.69-8.67). Gastrointestinal cancers including oesophagus, stomach, colorectal, biliary and pancreas cancers increased in MASLD (SHR, 1.13; 95% CI, 1.11-1.15), MetALD (SHR, 1.17; 95% CI, 1.14-1.21) and other combination aetiology (SHR, 1.09; 95% CI, 1.05-1.13). A modest increase in lung cancer and hormone-sensitive cancer was observed with MASLD. CONCLUSIONS: This study showed that MASLD and MetALD are associated with an increased risk of cancer, particularly liver and gastrointestinal cancers. The findings build new evidence for the clinical outcomes of MetALD while highlighting the importance of managing alcohol intake properly in MASLD and MetALD.

Analysis of Superspreading Potential from Transmission Clusters of COVID-19 in South Korea.

The COVID-19 pandemic has been spreading worldwide with more than 246 million confirmed cases and 5 million deaths across more than 200 countries as of October 2021. There have been multiple disease clusters, and transmission in South Korea continues. We aim to analyze COVID-19 clusters in Seoul from 4 March to 4 December 2020. A branching process model is employed to investigate the strength and heterogeneity of cluster-induced transmissions. We estimate the cluster-specific effective reproduction number Reff and the dispersion parameter κ using a maximum likelihood method. We also compute Rm as the mean secondary daily cases during the infection period with a cluster size m. As a result, a total of 61 clusters with 3088 cases are elucidated. The clusters are categorized into six groups, including religious groups, convalescent homes, and hospitals. The values of Reff and κ of all clusters are estimated to be 2.26 (95% CI: 2.02-2.53) and 0.20 (95% CI: 0.14-0.28), respectively. This indicates strong evidence for the occurrence of superspreading events in Seoul. The religious groups cluster has the largest value of Reff among all clusters, followed by workplaces, schools, and convalescent home clusters. Our results allow us to infer the presence or absence of superspreading events and to understand the cluster-specific characteristics of COVID-19 outbreaks. Therefore, more effective suppression strategies can be implemented to halt the ongoing or future cluster transmissions caused by small and sporadic clusters as well as large superspreading events.