“…Eighteen of these were single publications (Savage and Malt, 1992;Sugihara et al, 1993; Donato et al, 1994; Doci et al, 1995; Fernandez-Trigo et al, 1995; Fuhrman et al, 1995; Beckurts et al, 1997;Rees et al, 1997; Cady et al, 1998; Ohlsson et al, 1998;Riesener et al, 1998; Bradley et al, 1999; Harmon et al, 1999; Harms et al, 1999; Kemeny et al, 1999a; Bolton and Fuhrman, 2000; Okano et al, 2000; Moroz et al, 2002) and in a further 12 cases the data was obtained from multiple publications (Hughes et al, 1988(Hughes et al, , 1989 Hohenberger et al, 1990 Hohenberger et al, , 1994Scheele et al, 1990Scheele et al, , 1991Scheele et al, , 1995Scheele et al, , 1996Steele Jr et al, 1991Rosen et al, 1992; Gayowski et al, 1994;Stangl et al, 1994; Fong et al, 1995 Fong et al, , 1997 Fong et al, , 1999 Leslie et al, 1995; Jamison et al, 1996 Jamison et al, , 1997 Jenkins et al, 1997; Bakalakos et al, 1998a, b; Iwatsuki et al, 1999; Minagawa et al, 1999; Ambiru et al, 1999a; Kemeny et al, 1999b, c; Brand et al, 2000; DeMatteo et al, 2000; Minagawa et al, 2000). In addition, data on 30-day mortality and morbidity were included from a further nine studies (one with two publications) in which survival data was excluded owing to insufficient or unclear follow up (Minton and Abou-Issa, 1990; Fegiz et al, 1991; Nordlinger et al, 1992;van Ooijen et al, 1992;Wade et al, 1996; Lorenz et al, 1997 Lorenz et al, , 1998; Nadig et al, 1997; Taylor Just two studies included all patients presenting with colorectal liver metastases (Scheele et al, 1990(Scheele et al, , 1991(Scheele et al, , 1995(Scheele et al, , 1996Stangl et al, 1994; Harms et al, 1999) and only three studies presented data on all patients undergoing surgery (radical, nonradical and laparotomy) (Steele Jr et al, 1991 Fuhrman et al, 1995; Bakalakos et al, 1998a).…”