Clinical Effects of Chemotherapy Combined with Interferon-alpha in Colorectal Cancer

ABSTRACT

PURPOSE: In advanced colorectal cancer, 5-Fluorouracil (5-FU) and Leucovorin (LV) have been used as a standard chemotherapy regimen. 5-FU is a popular chemotherapeutic drug for colorectal cancers and LV is the most effective modulator of 5-FU. Recently, some studies using Interferon (INF) combination therapy with 5-FU to enhance the anti-tumor effect of 5-FU have been performed. The outcomes were reportet to be better than those of studies using single agent therapy. However, the clinical effect of a combination therapy with INF is still controversial. So that, we performed this study to understand the advantages of INF combination therapy in advanced colorectal cancers in the Korean population. METHODS: We recruited patients who had been diagnosed with for colorectal cancers and received operations and postoperative adjuvant chemotherapy in Uijongbu St. Mary's hospital, from July, 1995, to June, 1999. The patients were divided into two groups; control group treated with the Mayo clinic chemotherapy regimen of 5-FU plus LV, and study group treated with additional INF-alpha to 5-FU-LV combination treatment. We evaluated the clinical outcomes such as the overall survival rate, the recurrence rate, and the chemotoxicity between two groups. RESULTS: In comparison of 5 year survival rates of two groups for each stage of the colorectal cancer, those of stage B2 were 90.9% in the control group and 80.0% in the study group. For stage C patients, the values were 80.2% in control group and 52.5% in the study group. The overall 5-year survival rates of the control group and the study group regardless of stages were 77.1%, and 63.4%, respectively. The 5-year disease-free survival rates for stage B2 were 82.8% in the control group and 72.9% in the study group. For stage C patients, those were 42.6% in the control group and 34.4% in the study group. The recurrence and metastatic rates were 19.2% (local recurrence; 2, metastasis; 12) in the control group and 36.1% (local recurrence; 3 metastasis; 27) in the study group. The overall incidences of chemotoxicity were 24.7% in the control group and 31.3% in the study group. CONCLUSIONS: There was no evidence that chemotherapy using 5-FU and LV combined with INF-alpha in advanced colorectal cancer patients was more effective than the Mayo regimen of 5-FU and LV. More large scale clinical studies are warranted to evaluate the efficacy of additional INF therapy in colorectal cancer patients.