The significance of altered gastrointestinal permeability in cancer patients

The diagnosis and assessment of severity of intestinal mucosal damage in cancer patients treated by anticancer therapy still rely mostly on anamnestic data. We review here studies reporting on the use of intestinal permeability measurements in cancer patients before and during treatment.

The concept of intestinal permeability is based on differential permeability of intestinal mucosa to molecular markers, including monosaccharides and disaccharides, along the crypt-villus axis. Cytotoxic drugs and/or radiation impair replacement of intestinal epithelia and induce flattening of the villi, leading to increased exposure of luminal contents to crypts and increased disaccharide absorption. Increased disaccharide/monosaccharide ratio and decreased xylose absorption have been described in patients treated by radiotherapy as well as different cytotoxic or targeted agents across a spectrum of malignant disorders. Intestinal permeability changes correlated with clinical manifestations, including diarrhea, mucositis, neutropenic enterocolitis and systemic infections. The measurement of intestinal permeability has also been used as a surrogate end-point in interventional studies.

Intestinal permeability testing using nonmetabolized sugars may represent a tool for noninvasive objective assessment of intestinal toxicity of anticancer therapy.