Camptothecin Radiation Sensitization
The camptothecin analog CPT-11 has recently been approved for the treatment of 5-fluorouracil (5-FU)-resistant colorectal cancer (1), thus opening a new chapter in chemotherapeutic radiation sensitization. The camptothecins (CPT) are potent radiation sensitizers and are in their infancy in clinical studies. The combination of CPT with irradiation builds onto successful radiation-sensitization trials with 5-FU (2), because both classes of agents are cytotoxic for S-phase cells. They each have a defined role in the treatment of colorectal cancer, a site where radiation sensitization has improved local-regional control and overall survival (Table 1). Radiation sensitization with these agents is dose and schedule dependent and additional knowledge about this combination treatment, based on new laboratory data, may help optimize the use of the CPTs as radiosensitizers.
KeywordsMaximum Tolerate Dose Radiat Oncol Biol Phys Replication Fork Radiation Sensitization Lung Squamous Cell Carcinoma
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