A phase I study of oral uracil-ftorafur plus folinic acid in combination with weekly paclitaxel in patients with solid tumors

Gene expression analysis using human cancer xenografts to identify novel predictive marker genes for the efficacy of 5-fluorouracil-based drugs

The development of a diagnostic method for predicting the therapeutic efficacy or toxicity of anticancer drugs is a critical issue. We carried out a gene expression analysis to identify genes whose expression profiles were correlated with the sensitivity of 30 human tumor xenografts to 5-fluorouracil (5-FU)-based drugs (tegafur + uracil [UFT], tegafur + gimeracil + oteracil [S-1], 5'-deoxy-5-fluorouridine [5'-DFUR], and N4-pentyloxycarbonyl-5'-deoxy-5-fluorocytidine [capecitabine]), as well as three other drugs (cisplatin [CDDP], irinotecan hydrochloride [CPT-11], and paclitaxel) that have different modes of action. In the present study, we focused especially on the fluoropyrimidines. The efficacy of all anticancer drugs was assayed using human tumor xenografts in nude mice. The mRNA expression profile of each of these xenografts was analyzed using a Human Focus array. Correlation analysis between the gene expression profiles and the chemosensitivities of seven drugs identified 39 genes whose expression levels were correlated significantly with multidrug sensitivity, and we suggest that the angiogenic pathway plays a pivotal role in resistance to fluoropyrimidines. Furthermore, many genes showing specific correlations with each drug were also identified. Among the candidate genes associated with 5-FU resistance, the dihydropyrimidine dehydrogenase mRNA expression profiles of the tumors showed a significant negative correlation with chemosensitivity to all of the 5-FU based drugs except for S-1. Therefore, the administration of S-1 might be an effective strategy for the treatment of high dihydropyrimidine dehydrogenase-expressing tumors. The results of the present study may enhance the prediction of tumor response to anticancer drugs and contribute to the development of tailor-made chemotherapy.

Four Decades of Continuing Innovation With Fluorouracil: Current and Future Approaches to Fluorouracil Chemoradiation Therapy

Purpose

Chemoradiotherapy, the combination of external radiation therapy and concurrent chemotherapy, has been the basis for the oncologic management of many patients since its development in the 1960s. Fluorouracil (FU) chemoradiotherapy has demonstrated success in several organ sites with multiple dosing schedules that now guide the selection of oral analogs of FU to provide new chemoradiotherapy options.

Methods

This article reviews the metabolism and pharmacology of FU and the advantages of administration of FU by continuous infusion or bolus. The potential role and impact of the oral fluorouracil prodrugs UFT, S-1, BOF-A2, and capecitabine as replacements for intravenous administration are discussed. The results of recent chemoradiotherapy studies with FU from 2000 to 2003 are summarized in rectal, head and neck, esophageal, gastric, pancreatic, biliary, anal, and cervical cancers.

Results

Chemoradiotherapy with FU has the potential to widen the therapeutic window by minimizing normal tissue toxicity while maintaining effective tumor toxicity. Overall, FU chemoradiotherapy maximizes local control and, for some tumor sites (such as head and neck, pancreatic, biliary, cervical, esophageal, and gastric cancers), improves survival rates. Moreover, FU chemoradiotherapy results in improved organ preservation with excellent functional outcome in several anatomic sites including head and neck cancer, anal, and rectal cancer, with improved sphincter preservation.

Conclusion

FU chemoradiotherapy continues to play an important role in the management of many cancer sites. During the last four decades, optimal dosing schedules have produced a therapeutic gain. The introduction of oral prodrug analogs will likely further improve the results of FU therapy in several organ systems, such as the rectum, head and neck, and esophagus.