Kim K, Choi S, Lee G, et al. - Researchers intended to determine if there is an association between weight change and the future risk of developing hepatocellular carcinoma (HCC) in young adults. Data were gathered from the National Health Insurance Service database on more than 2.2 million men and women aged 20 to 39 who had no previous cancer diagnosis and underwent two consecutive biennial national health screenings between 2002 and 2005. There were 2,694 HCCs in men and 306 HCCs in women during 12 years of follow-up. In the multivariable Cox proportional hazards model adjusted for socioeconomic, health behavior, medical characteristics, and family history, weight gain of more than 5.0 kg and between 2.0 and 4.9 kg were linked to significantly increased risk in young men and young women, respectively. There was no evidence of a protective relationship between weight loss and HCC. The link between weight gain and HCC risk was stronger in young adults with underlying liver diseases than in those without any liver disease. Weight gain during young adulthood should not be overlooked clinically for future HCC risk, particularly in those with underlying liver disease.