Fluorouracil and leucovorin with or without interferon alfa-2a as adjuvant treatment, in patients with high-risk colon cancer: a randomized phase III study conducted by the Hellenic Cooperative Oncology Group.

BACKGROUND: It has been shown in randomized studies that adjuvant treatment with the combination of fluorouracil (FU) and levamisole reduced the risk of recurrence and deaths of patients with stage III colon cancer. Pharmacological studies of FU led to its use in combination with a number of modulating agents including interferon-alpha and leucovorin (LV) that appear to enhance its activity in vitro. Furthermore, a meta-analysis suggested that the combination of FU with LV increased the response rate as compared to FU monotherapy in patients with advanced colorectal cancer. PURPOSE: To evaluate the impact of adjuvant treatment with the combination of FU and LV with or without interferon alfa-2a (IFN) on disease-free survival (DFS) and overall survival (OS) for patients with stage II or III colon cancer. PATIENTS AND METHODS: From August 1989 to July 1997, 280 patients with stage II and III colon cancer entered the study and were randomly assigned to receive either the combination of FU (600 mg/m(2)/week x 6, followed by a 2-week rest) and LV (500 mg/m(2)/week x 6 as a 2-hour infusion, followed by a 2-week rest) for 4 cycles (group A, 139 patients), or the same chemotherapy plus recombinant IFN (3 MU subcutaneously 3 times a week) for 1 year (group B, 141 patients). RESULTS: A total of 109 patients (78.9%) of group A and 119 (84.4%) of group B completed four cycles of chemotherapy. Also, 51.4% of patients of group A and 53.9% of group B received > or =80% of the planned dose of FU. One patient (group A) was found to be ineligible and was not included in the analysis. The median relative dose intensity of FU in the two groups was 0.90 and 0.85, respectively. As of August 1998, after a median follow up of 4 years, there was no significant difference in either 3-year DFS (group A, 83.1%; group B, 75.9%, p = 0.14) or OS (group A, 84.5%; group B, 80.0%, p = 0.27). In the Cox model, stage of disease, number of infiltrated nodes, tumor grade and presence of regional implants were identified as significant prognostic factors for OS. Grade 3-4 toxicities, mainly diarrhea, were observed in 26.1% of patients of group A and in 24.8% of group B. There were no treatment-related deaths. CONCLUSIONS: The addition of IFN to the combination of FU with LV postoperatively does not improve DFS and OS of patients with stage II or III colon cancer.

Postoperative radiation and concomitant bolus fluorouracil with or without additional chemotherapy with fluorouracil and high-dose leucovorin in patients with high-risk rectal cancer: a randomized phase III study conducted by the Hellenic Cooperative Oncology Group.

BACKGROUND: Randomized studies have shown that postoperative chemotherapy with or without radiation therapy (RT) improved local control and survival of patients with stages II or III rectal cancer. However, the optimal sequence of treatments and the optimal chemotherapeutic regimen have not been defined. Modulation of fluorouracil (FU) by leucovorin (LV) has yielded a highly significant difference in response rate from that of FU monotherapy, as suggested by an overview of randomized trials in patients with advanced colorectal cancer. However, this difference in response rate did not translate into a survival benefit. PURPOSE: To evaluate the impact on the disease-free survival (DFS) and overall survival (OS) of patients with stages II or III rectal cancer of postoperative RT and concomitant bolus FU administration alone or with additional chemotherapy using FU and high-dose LV. PATIENTS AND METHODS: From October 1989 until February 1997, 220 patients were randomized postoperatively to receive either one cycle of chemotherapy with FU (600 mg/m2/week x 6 followed by a two-week rest) and leucovorin (LV, 500 mg/m2/week x 6 as a two-hour infusion) followed by pelvic RT with concomitant FU (400 mg/m2) as a rapid intravenous injection during the first three and last three days of RT, and three more cycles of the same chemotherapy with FU and LV (standard, group A, 111 patients) or pelvic RT with concomitant FU only (experimental, group B, 109 patients). RESULTS: As of August 1998, after a median follow-up of 4.9 years, there was no significant difference in either three-year DFS (Group A, 70.3%; group B, 68.2%, P = 0.53) or OS (group A, 77%; group B, 73.3%. P = 0.75). Cox multivariate analysis revealed stage of disease, number of infiltrated nodes, tumor grade, presence of regional implants and perforation to be significant prognostic factors. The incidence of severe side effects was significantly higher in the patients in group A than in those in group B (32.4% vs. 4.6%, P < 0.0001). CONCLUSIONS: The incorporation of additional chemotherapy with FU and LV into postoperative concomitant RT and bolus infusion of FU does not offer a > or = 10% three-year survival benefit over that of concomitant RT and bolus infusion of FU, and significantly increases toxicity in patients with stages II or III rectal cancer.

High-dose leucovorin, fluorouracil and oral dipyridamole in the treatment of advanced colorectal cancer.

Fifty-five patients with advanced colorectal cancer were treated with the combination of leucovorin (LV), fluorouracil (FU) and dipyridamole (DP). Two (4%) patients achieved a clinical complete remission, 4 (7%) a partial remission, 24 (44%) had stable disease while 25 (45%) patients progressed during the chemotherapy period. Median survival was 47 weeks and median time to progression 19.5 weeks. Major toxicities included diarrhea (66%), leukopenia (45%), anemia (50%) and nausea/vomiting (44%). In conclusion, the addition of oral DP does not appear to improve the efficacy of the standard LV/FU regimen in patients with advanced colorectal cancer.