The use of radiotherapy in early rectal cancer.

The treatment of early rectal cancer is mainly based upon different staging processes. If the tumour is suitable for a local excision, especially in low-lying tumours where an abdominal perineal excision is the alternative, a local procedure is often preferred. However, there is a clear shortage of doing a radical procedure in tumours involving the sphincter and sometimes the sphincter might be involved in the resection margin giving a bad bowel function.
According to data from the Swedish Cancer Register, the overall survival and cancer-specific survival of patients having been treated with a local excision are of similar magnitude as those treated with an abdominal procedure, if an analysis is done stage by stage. The use of radiotherapy in this specific group of patients has been very low.
The main use of radiotherapy could be in a preoperative setting to deliver a total downsizing of the tumour with no tumour left to operate upon, but also as a postoperative treatment if the pathological report after a local excision indicates a more aggressive tumour than interpreted from the beginning.
In a preoperative setting, it is rare that radiotherapy is used in abdominal surgery if the tumour is in an early stage (stage I). Due to the drawback of radiotherapy the use of preoperative radiotherapy has diminished over the years in this specific group. However, the new rational of giving chemo-radiotherapy in a preoperative setting with the purpose to more or less eradicate the tumour has changed the use of radiotherapy. Another type of preoperative treatment is the contact radiotherapy in stage I disease, where the tumour is totally eradicated by radiotherapy. This is like a local excision and is used in several units with an increasing use because new facilities are available nowadays.
The more common situation is a patient who has been treated with a local excision and the pathological report indicates an unfavourable tumour. The question in those patients is whether or not a salvage procedure with surgery should be done or if postoperative adjuvant radiotherapy with or without chemotherapy is appropriate. There are no randomised data supporting either of those two options and this is mainly a matter of information and discussion with the patient.
In summary, the use of radiotherapy in early rectal cancer (stage I) is rare and the evidence how to use it is more or less nonexistent.