A physiological approach to modernize the management of cancer chemotherapy-induced gastrointestinal toxicity

Gastrointestinal toxicity during chemotherapy is frequent. Symptomatic therapies for gastrointestinal toxicity, which do not address the underlying cause, may result in inadequate symptom control. With advances in curative treatment regimens, it becomes more important to minimize treatment toxicity which otherwise may compromise optimal chemotherapy and the chance of cure.

For decades, oncologists have concentrated on delineating the pathological processes, which occur within the gastrointestinal tract during chemotherapy treatment. However, pathological change does not in itself cause symptoms. Symptoms only arise when physiological functions are altered. In immunosuppressed patients, it is a priority to exclude infection as a cause for symptoms. In the presence of diarrhoea, the best investigative paradigm for this is stool culture, upper gastrointestinal endoscopy with duodenal biopsies and duodenal aspirate combined with flexible sigmoidoscopy and left colonic biopsies. Once infection has been excluded, although large studies have not been performed, case series repeatedly suggest that gastrointestinal symptoms arising during cancer chemotherapy can often be cured if newly acquired, gastrointestinal physiological deficits are identified.

Although many physiological changes induced by chemotherapy may be relatively transient and settle weeks or months after the end of treatment, during chemotherapy, their manifestations can be protean and severe. A systematic failure to research the frequency with which physiological causes of the symptoms are amenable to treatment has denied many patients' logical therapies for their chemotherapy-induced symptoms, and as a result, it is likely that symptomatic treatments are frequently suboptimal.