Cancer health disparities are characterized by adverse differences in cancer burden and outcomes, especially affecting populations of different ancestries. This is caused by a complex interplay between biological factors, including key molecular processes of the cell and social determinants of health. Current technology facilitates the classification of individuals using genetic ancestry markers, avoiding sociopolitical issues associated with self-reported ethnicity data. Such categorization has proved valuable in identifying ancestry-related molecular alterations that contribute to these disparities. This review examines the influence of molecular changes, including DNA methylation, genomic variations, and transcriptomic/proteomic patterns, on cancer progression, survival rates, treatment outcomes, and frequency of various cancer forms across ancestries. Finally, we address the historical overrepresentation of Caucasian populations in all aspects of cancer research, emphasizing the need for inclusive studies that reflect the genetic diversity of global populations.