Pitfalls in placebo-controlled trials in palliative care: dexamethasone for the palliation of malignant bowel obstruction.

To determine the effect of dexamethasone when treating malignant bowel obstruction, 35 patients were randomized to receive intravenous dexamethasone or a placebo, crossing over to the alternate treatment arm if there had been no resolution of obstruction by day 5. This was done in two consecutive studies. Patients were stratified according to whether or not they had received specific anticancer therapy within 28 days of study. In trial 1, 15 out of 22 patients 'responded' (resolution of obstruction by day 5; 10 on dexamethasone, five on placebo). Eleven out of 15 patients were 'on treatment'. In trial 2, six out of 13 responded (three on dexamethasone, three on placebo); three out of six were 'on treatment'. When both studies are combined, 60% (21/35) patients responded (13 on dexamethasone, eight on placebo). Poor patient accrual terminated both studies. Numbers are too small to allow a combination of studies or formal statistical analysis. We are unable to make any conclusion as to the effectiveness of dexamethasone in the palliation of malignant bowel disease.