A comprehensive review of 5-fluorouracil and leucovorin in patients with metastatic colorectal carcinoma

BACKGROUND: Colorectal carcinoma is the third leading cause of cancer-related death. The primary treatment for patients with metastatic colorectal carcinoma is systemic chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV), a biomodulator of 5-FU that has been shown to enhance its activity. Optimal dosing and administration strategies remain to be determined. METHODS: This article is a review of recent studies reporting on the use of high dose and low dose LV as a biomodulator of 5-FU in patients with advanced colorectal carcinoma. RESULTS: Studies of LV plus 5-FU demonstrated response rates of 7-58% in patients who had not received prior chemotherapy. A survival advantage was recorded in some trials. LV plus 5-FU produces mild and transient hematologic toxicity. The most common toxicities from LV plus 5-FU were gastrointestinal and schedule-dependent, but generally resolved within a few days. CONCLUSIONS: The combination of LV and 5-FU provides a favorable treatment regimen for patients with metastatic colorectal carcinoma. Growing evidence suggests that altering the dose and schedule of both LV and 5-FU can impact positively on the response rate. However, controversy remains regarding the optimal dosing regimen. Therefore, continued study of LV plus 5-FU is urged and a favorable impact on survival is requisite before definitive conclusions are drawn, particularly in relation to LV dosage.