If orthodox medicine were more effective in curing cancer and in providing supportive care, no doubt patients would rarely seek help from unorthodox practitioners. The available studies indicate that 25 to 45 per cent of patients have recourse to complementary treatments (Guex 1984a). Some turn to unorthodox therapies when orthodox medicine has failed (Bishop 1985) or has nothing further to offer (Thomson 1989), but many use such therapies to complement orthodox treatment in the hope of mitigating side-effects or improving their prognosis or their general health (Arkko et al. 1980; Vissing and Petersen 1981; Schraub et al. 1982; Guex 1983). Indeed, therapies often classed as ‘complementary’, such as relaxation and visualization, are available in some orthodox centres as ‘adjuvant’ treatments (Moorey and Greer 1989).