Assessment of gastrointestinal function and response to megesterol acetate in subjects with gastrointestinal cancers and weight loss

Background. Cancer-associated anorexia/cachexia syndrome (CACS) is common in advanced gastrointestinal malignancies and felt to be due primarily to cytokine-induced appetite suppression. Therapy with an appetite stimulant (megesterol acetate) is commonly employed, but results are sometimes disappointing. We hypothesize that CACS not only suppresses appetite but also interferes with gastrointestinal function. Methods. We conducted a prospective study in which 21 subjects with advanced gastrointestinal cancer and weight loss had digestive function. Patients were assessed using an indirect stable isotope method, and nutritional parameters were determined following which patients were treated with megesterol acetate for 4 weeks. Nutritional parameters were then reassessed, weight change determined, and the results were correlated with digestive function results obtained at the initiation of the study. Results. Abnormal gastrointestinal function based on the stable isotope test was common (86% of patients). The majority of the abnormal function appeared to be due to abnormal pancreatic function testing, in which 17/21 subjects recorded low results. Initial albumin, prealbumin, and carotene values were also frequently abnormal (55-65% of patients). Megesterol acetate therapy resulted in a weight gain in most (75%) patients, although serum albumin fell modestly in the group (average decrease of 0.2 mg/dl). However, prealbumin levels rose in 70% and carotene levels rose in 55%. The degree of weight gain was negatively correlated with previous self-reported weight loss (r=-0.53, p<0.05), and positively correlated (p<0.05) with pretherapy carotene (r=0.58), prealbumin (r=0.61) and the pancreatic function (digestive) phase of the digestive function test (r=0.41). Conclusion. These data suggest that abnormal digestive function is commonly seen in subjects with CACS and advanced gastrointestinal cancer, and that both pretherapy digestive function and nutritional status can predict or possibly influence the outcome of hormonal appetite stimulation therapy.