An Approach to Radiosensitizing Cervical Cancer by Use of Chemical Modulators of Nucleoside Metabolism.

Abstract

Although radiation alone is the treatment of choice for patients with cervical cancer that is not surgically respectable, locoregional failures rates approach 50% for locally advanced stages of disease. Therefore, decades of clinical trials using chemoradiotherapy have been performed in an attempt to enhance cure rates. Unfortunately, the addition of chemotherapy has not been shown to unequivocally improve outcome compared with radiation alone. Reasons for this include inadequate radiation doses, radiation treatment delays caused by higher acute toxicities of combined modality therapy, and insufficient understanding of both the optimal sequencing and mechanisms of radiosensitizers. Some of the chemotherapy agents tested include the fluoropyrmidines (5-fluorouracil [5-FU]), the halogenated thymidine analogues (iododeoyxuridine [IdUrd] and bromodeoyxuridine [BrdUrd] and hydroxyurea (HU). This article focuses on clinical results using these compounds, the evolving understanding of these different types of drug-radiation interactions, and potential new strategies for the use of these radiosensitizers in patients with locally advanced cervical cancer.