Targeted radiosensitization with DNA topoisomerase I drugs.

Extract: Radiation has become a mainstay therapy and currently provides care for approximately one half of the cancer population since its discovery more than a century ago. However, the efficacy of radiotherapy is largely restricted by the radiation-associated side effects, which in a way reflects the lack of tumor specificity of radiation. Drugs targeting DNA topoisomerase I (TOP1) are a novel class of anticancer agents with established activity against many cancers. In addition to their ability to kill cancer cells directly, these drugs are also excellent radiation sensitizers that can enhance the cell-killing effect of radiation. Combining TOP1-targeted drugs and radiotherapy represents a new promising cancer therapy. Here, we briefly review, from basic science to clinical application, the current status of targeted radiosensitization (RS) by combining TOP1 drugs with radiation.