Cancer, the emperor of all diseases, claimed 9.3 million lives in 2023, impacting individuals, communities, and healthcare systems. Its varied forms, like breast, colorectal, and skin cancers in men and women, inflict immense physical, mental, and economic strain, demanding urgent attention. Cancer is a genomic disorder produced by changes to genes, which is then characterized by inter- and intratumoral heterogeneity, leading to genetic alteration in patients. Conventional therapeutic strategies suffer from resistance to providing a desired therapeutic response. Evolving beyond one-size-fits-all, personalized cancer therapy leverages genetic insights and tumor diversity to craft precise treatments. This chapter delves into this emerging field, exploring how tailored therapies, informed by individual genomes and lifestyles, can impact a patient’s life. This evidence-based approach aims for optimal efficacy and minimal side effects. From understanding complex data sets to customizing dosages, we look into the challenges and solutions of this promising paradigm shift in cancer care.