Silica core and non-silica-based shell nanoconstructs represent a promising advancement in cancer theranostics by integrating diagnostic and therapeutic functions within a single nanoparticle system. The silica core offers a robust, tunable platform with high surface area and biocompatibility, while the non-silica-based shell enhances properties such as targeted drug delivery and controlled release. These nanoconstructs can be engineered for optimal size, surface charge, and functionalization, allowing for precise targeting of tumor cells while reducing systemic toxicity. Various non-silica shell materials, such as polymers, lipids, and other inorganic compounds, enhance drug loading, improve stability, and enable multifunctional capabilities. Functionalization of the surface with targeting ligands further improves tumor specificity, making them ideal candidates for both imaging and therapy. The silica core provides excellent contrast for imaging techniques like CT and ultrasound, while the non-silica shell offers the potential for photothermal, photodynamic, or chemotherapeutic applications. These hybrid nanostructures have demonstrated their potential in transforming cancer diagnosis and treatment through innovative synthesis and design approaches, offering a versatile platform for theranostic applications.