Familial coaggregation of MASLD with hepatocellular carcinoma and adverse liver outcomes: Nationwide multigenerational cohort study

•Nationwide multigenerational study of 292,274 family members of people with biopsy-confirmed MASLD and comparators.•MASLD first-degree relatives had increased hazards of HCC, major adverse liver outcomes and liver-related mortality.•The absolute risk of HCC was low, with only one extra case per 900 first-degree relatives over 20 years of follow-up.•Spouses of individuals with MASLD also had a higher relative risk of developing major adverse liver outcomes.•Liver disease progressed more rapidly in MASLD first-degree relatives with concomitant liver diseases. Background & AimsMetabolic dysfunction-associated steatotic liver disease (MASLD; formerly NAFLD) is the fastest growing cause of hepatocellular carcinoma (HCC) worldwide. However, whether family members of individuals with MASLD also share an increased risk of developing HCC is unknown.MethodsThis nationwide multigenerational cohort study involved family members of all Swedish adults diagnosed with biopsy-proven MASLD (1969−2017), and matched general population comparators. Using the Swedish Multi-generation Register, we identified 38,018 first-degree relatives (FDRs: parents, siblings, offspring) and 9,381 spouses of patients with MASLD, as well as 197,303 comparator FDRs and 47,572 comparator spouses. We used Cox proportional hazards models to calculate adjusted hazard ratios (aHRs) for HCC, major adverse liver outcomes (cirrhosis, decompensated liver disease or liver transplantation), liver-related mortality, extrahepatic cancer, and non-liver-related mortality.ResultsOver a median of 17.6 years, the rate of the primary outcome HCC was higher in MASLD FDRs vs. comparator FDRs (13 vs. 8/100,000 person-years [PY]; aHR 1.80, 95% CI 1.36−2.37). The HCC risk was further increased in FDRs of individuals with liver fibrosis/cirrhosis (aHR 2.14, 95% CI 1.07−4.27; PHeterogeneity = 0.03). MASLD FDRs also had higher rates of major adverse liver outcomes (73 vs. 51/100,000 PY; aHR 1.52, 95% CI 1.36−1.69) and liver-related mortality (20 vs. 11/100,000 PY; aHR 2.14, 95% CI 1.67−2.74). MASLD FDRs with any concomitant chronic liver condition experienced accelerated progression of liver disease (aHR 1.47, 95% CI 1.29-1.67). MASLD spouses were at higher risks of major adverse liver outcomes (86 vs. 74/100,000 PY; aHR 1.23, 95% CI 1.01−1.51) and liver-related mortality (25 vs. 19/100,000 PY; aHR 1.93, 95% CI 1.15−3.23), but not of HCC (aHR 1.43, 95% CI 0.87−2.35).ConclusionsThere is distinct familial clustering of adverse liver-related outcomes in families of individuals with biopsy-proven MASLD, with higher relative risks of HCC, progressive liver disease, and liver-related mortality, but absolute risks are low.Impact and implicationsMetabolic dysfunction-associated steatotic liver disease (MASLD; formerly termed NAFLD) clusters in families with high genetic susceptibility and shared environmental risk factors, but the risks of developing hepatocellular carcinoma and other major liver-related outcomes in family members of individuals with MASLD are largely unknown. This large nationwide multigenerational cohort study involving family members (first-degree relatives and spouses) of individuals with biopsy-proven MASLD and of matched general population comparators found slightly increased risks of hepatocellular carcinoma in first-degree relatives, and of developing cirrhosis and liver-related mortality in all family members of individuals with biopsy-proven MASLD. The findings of this study provide large-scale evidence to inform clinical practice guidelines for recommendations on the early identification of individuals at higher risk of liver-related morbidity and mortality. Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly NAFLD) is the fastest growing cause of hepatocellular carcinoma (HCC) worldwide. However, whether family members of individuals with MASLD also share an increased risk of developing HCC is unknown. This nationwide multigenerational cohort study involved family members of all Swedish adults diagnosed with biopsy-proven MASLD (1969−2017), and matched general population comparators. Using the Swedish Multi-generation Register, we identified 38,018 first-degree relatives (FDRs: parents, siblings, offspring) and 9,381 spouses of patients with MASLD, as well as 197,303 comparator FDRs and 47,572 comparator spouses. We used Cox proportional hazards models to calculate adjusted hazard ratios (aHRs) for HCC, major adverse liver outcomes (cirrhosis, decompensated liver disease or liver transplantation), liver-related mortality, extrahepatic cancer, and non-liver-related mortality. Over a median of 17.6 years, the rate of the primary outcome HCC was higher in MASLD FDRs vs. comparator FDRs (13 vs. 8/100,000 person-years [PY]; aHR 1.80, 95% CI 1.36−2.37). The HCC risk was further increased in FDRs of individuals with liver fibrosis/cirrhosis (aHR 2.14, 95% CI 1.07−4.27; PHeterogeneity = 0.03). MASLD FDRs also had higher rates of major adverse liver outcomes (73 vs. 51/100,000 PY; aHR 1.52, 95% CI 1.36−1.69) and liver-related mortality (20 vs. 11/100,000 PY; aHR 2.14, 95% CI 1.67−2.74). MASLD FDRs with any concomitant chronic liver condition experienced accelerated progression of liver disease (aHR 1.47, 95% CI 1.29-1.67). MASLD spouses were at higher risks of major adverse liver outcomes (86 vs. 74/100,000 PY; aHR 1.23, 95% CI 1.01−1.51) and liver-related mortality (25 vs. 19/100,000 PY; aHR 1.93, 95% CI 1.15−3.23), but not of HCC (aHR 1.43, 95% CI 0.87−2.35). There is distinct familial clustering of adverse liver-related outcomes in families of individuals with biopsy-proven MASLD, with higher relative risks of HCC, progressive liver disease, and liver-related mortality, but absolute risks are low.