Background: Systemic adjuvant chemotherapy can improve overall survival and reduce the incidence of distant metastases for patients with advanced colon cancer. This study aimed to investigate whether regional chemotherapy (given by intraperitoneal or intraportal methods) combined with systemic chemotherapy was more effective than was systemic chemotherapy alone in terms of survival and recurrence for patients with stage II-III colorectal cancer. The study also compared systemic chemotherapy with fluorouracil and folinic acid with that of fluorouracil and levamisole.
Methods: During surgery, 753 patients with stage II-III colorectal cancer were randomly assigned to systemic chemotherapy alone (379 with fluorouracil and folinic acid, and 374 with fluorouracil and levamisole), and 748 to postoperative regional chemotherapy with fluorouracil followed by systemic chemotherapy with fluorouracil and folinic acid (n=368) or with fluorouracil and levamisole (n=380). Regional chemotherapy was given intraperitoneally (n=415) or intraportally (n=235) according to institution. The primary endpoint was 5-year overall survival. Secondary endpoints were 5-year disease-free survival and toxic effects. Analyses were by intention to treat.
Findings: Median follow-up was 6.8 years (range 0.0-10.1). 5-year overall survival was 72.3% (95% CI 69.0-75.6) for patients assigned regional and systemic chemotherapy, compared with 72.0% (68.7-75.3) for those assigned systemic chemotherapy alone (hazard ratio [HR] 0.97 [0.81-1.15], p=0.69). 5-year overall survival for all patients assigned fluorouracil and levamisole was 72.0% (68.7-75.2) compared with 72.3% (69.0-75.6) for all those assigned fluorouracil and folinic acid (HR 0.98 [0.82-1.17], p=0.81). The hazard ratios for 5-year disease-free survival were 0.94 (0.80-1.10) for regional versus non-regional treatment, and 0.92 (0.79-1.08) for all fluorouracil and levamisole versus fluorouracil and folinic acid. Grade 3-4 toxic effects were low in all groups.
Interpretation: Fluorouracil-based regional chemotherapy adds no further benefit to that obtained with systemic chemotherapy alone in patients with advanced colorectal cancer.