Zhang X, et al. - Given a considerable disparity in incidence rates for hepatocellular carcinoma (HCC) by age, gender, and race/ethnicity, researchers examined if HCC among sub-groups of the population by age, gender, race/ethnicity, and birth cohort are uniform or if they interact with each other or have changed over time. From the US Cancer Statistics registry, data were assessed for this work. Between 2001 and 2015, men and women ≥ 50 years exhibited an increase in HCC rates, women aged 40-49 had stable HCC rates, but males aged 40-44 and 45-49 had a decrease in HCC rates. This resulted in a decrease in the male-to-female incidence rate ratio (IRR) among persons aged < 50 from 4.63 in 2001 to 2.42 in 2015, however, the ratio remained stable over time among persons aged ≥ 50. Successive cohorts of males born after circa 1956 had lower HCC rates, while females born circa 1991 had higher HCC rates than those among females born circa 1956. These findings suggest that the epidemiology of HCC is changing from a disease with striking male predominance to one with less male predominance.