The role of radiotherapy in the palliative treatment of gastrointestinal cancer.

Gastrointestinal malignancy is the second commonest cancer and is associated with a high mortality. Although definitive surgery could be offered for most tumour sites in the gastrointestinal tract, the majority of patients will still develop incurable recurrent or metastatic disease. Therefore, palliation is an important part of management. Radiotherapy has long been recognized as an effective palliative modality in gastrointestinal cancer. It was previously offered in cases where surgical resection was not feasible either due to the advanced nature of the disease or the presence of metastatic disease. Planning and delivery of radiation techniques have improved over the years and it is now possible to offer high-dose radiation to the tumour with acceptable side-effects. The dose of radiation offered is important to achieve worthwhile palliation. The advent of high-dose brachytherapy has contributed significantly to the role of radiotherapy as an effective palliative modality used either alone or as a boost to external beam radiotherapy. The addition of chemotherapy to radiation has been used in most tumour sites in the gastrointestinal tract and has been shown to improve the therapeutic ratio; however, one should be aware of the increased toxicity and careful selection of patients is necessary. Chemoradiation could help to down-stage locally advanced tumours which are otherwise unresectable. This approach has led to improved local control in certain tumour sites, e.g. anal canal and oesophagus. Whether this translates into improvement in survival remains to be seen. However, with increasing use of multi-modality therapy, increases in toxicity to the patient and in cost to healthcare providers must be taken into account.