mRNA vaccines against SARS-CoV-2 have generated significant curiosity and interest in the mRNA platform. Due to production and storage limitations, as well as limited efficacy, the RNA platform has been continuously studied, leading to the emergence of new technologies, including self-amplifying RNA (saRNA), trans-amplifying RNA (taRNA), and finally, circular RNA (circRNA). The latter platform was discovered many years ago, but only recently has piqued researchers’ interest. Notwithstanding the possibility of delivering RNA molecules without the use of nanocarriers, delivery efficacy is lower, and thus, required doses are higher. Consequently, the use of nanotechnology has improved the delivery efficacy of these technologies to target cells, as it enables RNA protection from nucleases, while promoting some level of organ specificity. Currently, lipid-based nanoparticles are the gold-standard nanocarriers used to encapsulate these RNA classes. Different studies are ongoing to evaluate the efficacy of these RNA classes in oncological diseases, aiming at improving the life expectancy of cancer patients.