“…The American Cancer Society estimated that in 1995 more than 130 000 new cases of CRC would be diagnosed in the USA and that there would be 54 900 deaths from the disease (American Cancer Society, 1995). CRC onset and its progression has been studied extensively at the molecular (Bos et al, 1987;Forrester et al, 1987;Vogelstein et al, 1988;Burmer and Loeb, 1989;Delattre et al, 1989;Kern et al, 1989;Vogelstein et al, 1989;Fearon and Vogelstein, 1990;El-Deiry et al, 1991;Oudejans et al, 1991;Houlston et al, 1992;Laurent-Puig et al, 1992;Offerhaus et al, 1992;Sharrard et al, 1992;Bell et al, 1993;Finkelstein et al, 1993a and b;McLellan et al, 1993;Peltomaki et al, 1993;Urosevic et al, 1993;Breivik et al, 1994;Dix et al, 1994;Moerkerk et al, 1994;Morrin et al, 1994;Tanaka et al, 1994;Giaretti et al, 1995;Laird et al, 1995;Lewis et al, 1996;Span et al, 1996) and genetic (Woolf et al, 1958;Macklin et al, 1960;Houlston et al, 1992;Zhao and Le Marchand, 1992;Peltomaki et al, 1993;Goldgar et al, 1994;Lewis et al, 1996) levels and there is a commonly accepted model relating tumour grade according to Dukes' stage (Dukes, 1932) to specific DNA changes …”