EDITOR,—Maurice L Slevin's editorial on adjuvant treatment in colorectal cancer reflects the prevailing conviction among oncologists about the beneficial effect of chemotherapy on survival in this disease.1 Unfortunately, Slevin probably overestimates the real effect because he selectively emphasises particular trials that have reported a survival benefit while ignoring other studies, testing identical regimens, in which no benefit was apparent (N Wilking, Stockholm colorectal cancer symposium, Stockholm, 12-13 Oct 1995).2 3 Moreover, even in those trials cited, the reported improvements in survival are …