“…This left 23 randomised controlled trials with survival data (Arcangeli et al, 1983;Cachin et al, 1977;Ervin et al, 1987;Fazekas et al, 1980;Fu et al, 1987;Gollin et al, 1972;Gupta et al, 1987;Head and Neck Contracts Program, 1987;Holoye et al, 1985;Hussey & Abrams, 1975;Knowlton et al, 1975;Lo et al, 1976;Martin et al, 1986;Nissenbaum et al, 1984;Pearlman et al, 1985;Petrovich et al, 1981;Rentschler et al, 1987;Schuller et al, 1988;Stefani et al, 1971;Stefani & Chung, 1980;Stell et al, 1983;Stolwijk et al, 1983;Taylor et al, 1985;Toohill et al, 1987;Vermund et al, 1985 Gollin et al (1972) and a subgroup of patients with tumours of the oral cavity and oropharynx, with additional patients, was later reported by Lo et al (1976). The data for tumours of the mouth and oropharynx are taken from the latter paper, and those for other sites from the former, but the two are otherwise treated as one trial.…”