Care after cancer therapy: the ignored but curable bowel problems of the irradiated patient

The Royal Marsden Hospital, Fulham Road, SW3 6JJ London, United Kingdom

Abstract

Following radical pelvic radiotherapy, 90% of patients will report a permanent change in bowel habit, 50% say that gastrointestinal symptoms affect their quality of life and 20-40% (depending on the primary tumour site treated) say the effect on quality of life is moderate or severe. The number of long term survivors is increasing. Many affected patients never get referred to a gastroenterologist.

Radiotherapy does not respect natural anatomical boundaries. Widely separated parts of the gastrointestinal tract may lie in the path of the radiotherapy beam and be subject to damage. Chronic symptoms after treatment mainly develop because radiation induces specific change in one or more specific physiological functions in exposed areas of the gastrointestinal tract. This may cause symptoms in its own right or may destabilise pre-existing conditions or subclinical disease which in turn cases symptoms. Thirdly, new diseases may manifest themselves after radiotherapy and be confused with symptoms induced by the radiotherapy.

The same symptoms may be caused by different functional deficits. Many patients have more than one cause for their symptoms, which require very different treatments. Almost all deficits in gastrointestinal function induced by radiotherapy can be treated effectively if they can be accurately diagnosed. Simple diagnostic tests used in other contexts if applied appropriately to patients with new gastrointestinal symptoms after radiotherapy, can identify the underlying cause(s) of new onset symptoms. Empirical treatment often fails because it is difficult to predict the combination of treatments which are required. There is increasing evidence that many patients have unusual but highly treatable malfunctions of gastrointestinal physiology, which if correctly diagnosed, means that a patient with difficult symptoms can frequently be helped.

There is also increasing evidence that the underlying pathological processes (namely ischaemia and fibrosis) which lead to physiological loss are preventable or reversible. Pharmaceutical and dietary prevention of chronic toxicity must become a greater component of oncological treatments in the future.