The advent of molecular and genetic advancement in the field of oncology research has led to a shift in the treatment of various forms of cancer from traditional chemotherapeutics to targeted therapy. The principle behind targeted therapy is utilizing therapeutics designed to interfere with specific molecules that have a relatively specific or higher expression profile in cancer cells and are critical for cancer growth and progression. These were designed as mechanistic therapeutics in the form of small molecules and monoclonal antibodies. Currently, they have been modified to incorporate passive or active targeting delivery systems to improve their specific distribution and enhance cytotoxicity towards cancer cells while simultaneously reducing their systemic toxicity profile. Passive targeting employs encapsulated delivery systems to take advantage of the enhanced permeation and retention effect of the tumor microenvironment, while active targeting relies on receptor mediated interactions, such as cell surface ligands conjugated to the therapeutic moiety. A synergistic strategy for cancer therapy is evolving, where precision medicine acts as a diagnostic prerequisite for targeted therapy via prognostic biomarkers and tumor genotyping. Despite the plethora of research undertaken in targeted therapy, limited numbers were approved for clinical use, and significant challenges remain to be addressed.
Part of the book: Tumor Progression and Metastasis