Background: Cancer, although it has a multifactorial origin, is primarily linked to genetic dysregulation that results in alterations in genes involved in cellular processes. In this sense, RNA interference (RNAi) emerges as a gene silencing strategy with the ability to degrade a specific messenger RNA sequence responsible for the development or maintenance of the carcinogenic process. Aim: Thus, the objective of this summary is to analyze the development of RNAi technology over the years, as well as its application in personalized oncological therapies. Methodology: A search for articles was conducted in the PubMed database using the descriptors "RNA interference," "cancer," and "precision medicine." Articles in English, from the period of 2005 to 2025, related to the topic of the summary were selected. Results: Through the reading of the six selected articles, it is noted that, after the discovery of RNAi in the 1990s, there was an increase in understanding of the silencing mechanism. Furthermore, there is an increased recognition of the necessity for delivery methods and modulation of off-target effects to enhance efficiency. As sequencing techniques improve, precision medicine has directed RNAi to suppress specific mutations, such as the use of siRNAs against KRAS G12D or tumor markers in patients. Furthermore, microRNA (miRNA) can be employed as a target for an immunosuppressor, oncogene, and biomarker. RNAi has also been examined in combination with immune checkpoint inhibitors and other drugs, in which subsequent advances, such as the use of lipid nanoparticles, resulted in the approval of Patisiran by the Food and Drug Administration in 2018. Although it does not treat cancer, it was the first clinically authorized RNAi drug, paving the way for new research recently. Conclusion: Consequently, the understanding of RNAi has advanced, facilitating personalized medicine, the development of therapeutic strategies and the identification of tumor biomarkers.