Abstract :
The efficacy of adjuvant chemotherapy after surgery for colorectal cancer remains unproven. We have investigated the efficacy of a perioperative intraportal cytotoxic regimen in a randomised trial of 533 patients with operable colorectal carcinoma. Patients were randomly assigned either a single course of portal infusion with mitomycin (10 mg/m2, one dose) plus fluorouracil (500 mg/m2 per 24 h for 7 days) starting immediately after surgery, or no adjuvant treatment. 505 (94%) were evaluable. At median follow-up of 8 years, adjuvant therapy reduced the risk of recurrence by 21% (hazard ratio 0·79 [95% Cl 0·62-1·00], P=0·051) and the risk of death by 26% (0·74 [0·57-0·97], P=0·026). The lower risk of relapse was observed in all subgroups based on node status or localisation of the tumour; the risk reduction was greatest in patients with tumour-involved lymph nodes (Dukesʹ C; 0·67 [0·45-0·99], P=0·045) and for those with colon cancer (0·78 [0·56-1·09], P=0·151). Most of the difference in overall and disease-free survival could be attributed to a consistent reduction of all kinds of tumour recurrences (local relapses, liver metastases, and other distant metastases) in the treated group, rather than to a reduction of liver relapses only. We conclude that part of the benefit obtained with a single course of adjuvant chemotherapy via the portal vein for patients with operable colorectal carcinoma might be due to the systemic effects of the portal chemotherapy.
