Biodegradable polymers such as Polycaprolactone (PCL), Polylactic acid (PLA), and Poly(lactic-co-glycolic acid) (PLGA) are attracting attention as key platforms for anticancer drug delivery systems due to their excellent biocompatibility and controllable degradation rates. These polymers can overcome limitations of existing chemotherapeutics, such as low bioavailability, systemic toxicity, and nonspecific cell damage, and contribute to the development of precision medicine approaches and long-acting therapeutics. This paper discusses the chemical and physicochemical properties of these three polymers, their synthetic strategies, and the controlled drug release technology through surface functionalization and stimuli-responsive design. Furthermore, we highlight their potential for use in various formulations, including micelles, nanoparticles, hydrogels, and microspheres, enabling enhanced drug solubility, sustained release, and tumor targeting. Preclinical and clinical applications demonstrate that these polymer-based DDSs represent a promising approach for implementing next-generation precision anticancer treatment strategies, with further potential for clinical translation and widespread adoption.