ONCOLOGY Vol 12 No 10

The cycle-specific schedule-dependent antimetabolite 5-fluorouracil (5-FU) has been in clinical use for 40 years and has evolved as an important agent in the treatment of a large spectrum of tumors, including all gastrointestinal

Over the past several years, the pyrimidine catabolic pathway and, in particular, the first enzymatic step involving dihydropyrimidine dehydrogenase (DPD) have been recognized as being critical in determining the ultimate

The treatment of advanced colorectal cancer has been evaluated in a series of randomized trials, including infusional and modulated 5-fluorouracil (5-FU), and three meta-analyses encompassing trials of 5-FU plus

The optimal management of patients with lymph node-positive prostate cancer remains controversial. The role of pelvic irradiation in patients at high risk for nodal involvement continues to be debated. Studies of prostate

Eniluracil is a potent inactivator of dihydropyrimidine dehydrogenase (DPD), which is the first enzyme in the degradative pathway of systemically administered 5-fluorouracil (5-FU). Two completely oral regimens of eniluracil plus 5-FU are being evaluated in clinical trials: (1) a chronic schedule with both agents administered BID in a 10:1 ratio for 28 days of a 5-week course, and (2) a 5-day schedule of eniluracil once daily on days 1 through 7 and 5-FU once daily on days 2 through 6. The clinical development of eniluracil is being pursued in several tumor types, including colorectal cancer, breast cancer, and pancreatic cancer. Response rates achieved in a phase II study of the chronic schedule of oral eniluracil/5-FU in patients with colorectal cancer compare favorably with those obtained in trials of intravenous 5-FU and leucovorin, while results from other trials are awaited. Safety analysis for the 28-day schedule has revealed a low incidence of severe toxicities, particularly as compared with standard 5-FU regimens. [ONCOLOGY 12(Suppl 7):52-56, 1998]

Although gastric carcinoma is an uncommon disease in North America, its incidence is alarmingly high in Asia, South America, Eastern Europe, and countries of the former Soviet Union. Screening for gastric carcinoma is performed only on a limited basis in Japan; in the rest of the world, therefore, patients often present with advanced disease at the time of diagnosis.

The common clinical presentations of head and neck cancer include early (stage I or II) disease, locally or regionally advanced (stage III or IV, M0) disease, and recurrent or metastatic disease (< 5% of patients).

Discussed herein are selected oral fluorinated pyrimidines that are converted to 5-fluorouracil (5-FU) in vivo to exert antitumor activity. These agents include capecitabine (Xeloda), tegafur-uracil (UFT) plus leucovorin (Orzel), and S-1 (BMS247616). These agents offer the convenience of an orally administered therapy with potentially fewer toxic effects than conventional bolus regimens of 5-FU plus leucovorin. These oral agents provide prolonged 5-FU exposure at lower peak concentrations than observed with bolus intravenous administration of 5-FU and may confer pharmacoeconomic advantages by reducing administration costs and toxicity-related hospitalizations. These regimens also have the potential for improved therapeutic activity by achieving higher 5-FU concentrations in the tumor or by biochemically modulating 5-FU. Phase III trials in patients with advanced colorectal carcinomas are comparing the antitumor activity of these agents with that of intravenous 5-FU plus leucovorin. [ONCOLOGY 12(Suppl 7):48-51, 1998]

The cellular and clinical pharmacology of fluoropyrimidines is characterized by marked interpatient variability in tumor response and patient tolerance. Understanding the metabolic pathways followed by 5-fluorouracil (5-FU) has

In 1992, the FDA decided that silicone gel-filled breast implants would be available only through controlled clinical studies, despite the fact that they had been used for mammoplasty in millions of women around the world

Three oral 5-fluorouracil (5-FU) therapies have been approved by the US Food and Drug Administration or are in development for the treatment of patients with breast cancer: capecitabine, UFT, and 5-FU/eniluracil.

Metastatic colorectal cancer to the liver develops in over 50,000 US patients each year and is rapidly fatal if untreated. Even the most active chemotherapeutic agents rarely prolong survival for more than 3 years. Liver