Intestinal absorption in breast cancer patients

Although the absorptive functions of the intestine in extraintestinal cancer patients may play a role in the genesis of cancer cachexia, no extensive study has been made in this area. We have evaluated both active and passive absorption in 15 stage IV breast cancer patients, using an oral load of 4 sugars whose 5-hour urinary concentrations were measured by chromatography. The monosaccharides 3-o-methylglucose and xylose were chosen to evaluate active and facilitated absorption respectively, while rhamnose and lactulose demonstrated passive absorption through small cell pores and intracellular tight junctions respectively. Test results indicated a significantly increased passive absorption via tight junctions in cancer patients as compared to 22 age-matched healthy control subjects; this finding suggests a partial loss of the barrier function of the intestine. Low urinary concentrations of 3-o-methylglucose and xylose after the oral load showed a markedly reduced capacity for active and facilitated absorption in these patients. These findings merit confirmation by similar studies of other extraintestinal cancers, and suggest interesting possibilities which could have theoretical (pathogenesis of neoplastic malnutrition) and practical value (enteral or parenteral therapy to counteract cancer cachexia).