Summary Patients with breast cancer treated with MPA often report an improvement in appetite. Similar appetite stimulation is seen in patients treated with some corticosteroids, but MPA has a potential advantage over these drugs in that it does not exert a catabolic effect. MPA (100 mg tds orally) has therefore been compared with placebo in 60 patients with advanced malignant disease. Twenty-one patients in the MPA group and 20 in the placebo group were receiving chemotherapy. Patients were treated for 6 weeks and were assessed at weeks 0, 3 and 6 for appetite, energy, mood and pain using visual analogue scales. Nutritional status was assessed by the measurement of serum proteins and anthropometrics. Karnofsky score was recorded as a measure of performance status.There was a significant improvement in appetite in the MPA group between weeks 0 (pre-study) and 3 (P = 0.0002) and 0 and 6 (P = 0.015). There was no significant improvement in appetite in the placebo group. Supporting this finding was the significant increase in serum thyroid binding pre-albumin and retinol binding protein in the MPA group between weeks 0 and 3 and 0 and 6 (P = 0.023 and P = 0.039 respectively). These two parameters showed no significant change in the placebo group Anorexia is a debilitating symptom commonly experience by cancer patients (Theologides, 1977). It is a component of protein-energy malnutrition which is associated with a poor prognosis, reduced response to anti-neoplastic therapy and a reduced quality of life (Holmes & Dickerson, 1987). In a study of 126 cancer patients receiving chemotherapy or radiotherapy Padilla et al. reported that appetite and the ability to eat were the most important factors in the physical aspects of the patients' quality of life. These factors were more important in determining quality of life than the ability to work, physical strength or sexual satisfaction (Padilla, 1986). The background to this often profound loss of appetite and the weight loss that accompanies cancer is complex and agreement on the underlying mechanism has not been reached (Bernstein & Symundi, 1980). Psychological, emotional or physiological factors due to the disease and treatment may initiate or worsen anorexia, but as the disease progresses it is usually the cancer itself that is the main cause of the anorexia (Theologides, 1977 (Goodinson, 1987a). More recently a number of studies have investigated the use of biochemical testing in nutritional assessment, with particular reference to plasma proteins (Mullen & Torosian, 1981;Inglebleek et al., 1975;Carpentier et al., 1982;Ota et al., 1985;Thean et al., 1988;Weisberg, 1983). Those (Aitken, 1969). As an instrument they allow a measurement of changes in subjective feelings within individual patients over a set time. These scales have been validated for reliability, between subject reliability, test-retest reliability and validity by Silverstone (1982).