Background: 5-fluorouracil-based adjuvant chemotherapy after surgical resection of colon cancer is standard treatment. However, the choice of best delivery route--that is, systemic (i.e., intravenous or oral) or regional (i.e., intraportal, intraperitoneal, or hepatic arterial infusion)--has been controversial. In a randomized clinical trial of patients with colon cancer, we compared the benefits of chemotherapy delivered by these routes individually or in combination.
Methods: From April 2, 1992, through April 30, 1998, 1084 eligible patients with Dukes' stage B or C colon carcinoma were randomly assigned: 369 patients to the IP regimen (continuous portal vein infusion of 5-fluorouracil at 500 mg/m2 of body surface daily and heparin at 5000 IU daily for 7 consecutive days, beginning on the day of surgery), 358 patients to the SY regimen (six 28-day courses of systemic leucovorin at 100 mg/m2 daily on days 1 through 5 followed by systemic bolus 5-fluorouracil at 370 mg/m2 daily on days 1 through 5, with treatment initiated 15-35 days after surgery), and 357 patients to the IP+SY regimen (the IP regimen followed by the SY regimen, with the same scheduling). Primary survival was analyzed with the log-rank statistic and a Cox multivariable regression model. All statistical tests were two sided.
Results: At a median follow-up time of 99 months, 389 events (recurrences, second malignancies, or deaths) had occurred, and 361 patients died. Sites of first recurrences were similar among the three arms. At 5 years, overall and event-free survival rates were similar among those on the IP (74% and 68%, respectively), SY (78% and 71%), and IP+SY (73% and 67%) regimens. When compared with the group on the SY regimen, the risk for death associated with the IP regimen (hazard ratio [HR] = 1.05, 95% confidence interval [CI] = 0.82 to 1.36) was similar to that associated with the IP+SY regimen (HR = 1.12, 95% CI = 0.78 to 1.45) (P =.69), as were the risks for first event (HR = 1.07, 95% CI = 0.84 to 1.37 and HR = 1.10, 95% CI = 0.86 to 1.41, respectively) (P=.74).
Conclusion: Overall and event-free survival rates were similar in all three arms. The combined regimen was no better than either single regimen alone.