ABSTRACT
In the primary treatment for rectal cancer, surgery plays the most important role. The overall 5-year survival figures have slowly improved during recent decades, and today slightly more than 50% of all patients with rectal cancer will survive.1,2 Between 20% and 30% of all newly diagnosed patients with rectal cancer have already developed distant metastases and/or have a locally inoperable tumour. Among those having undergone apparently curative surgery, the two main reasons for a fatal outcome are occult distant metastases not found at surgery and/or a locoregional recurrence. During the past 20 years or so, the average locoregional recurrence rate, as reported from all controlled trials worldwide, has been 29%.3 In the light of the high morbidity and mortality from a local failure, this is an unacceptedly high figure. This is particularly so since the majority of local recurrences are probably due to inappropriate surgery. Recent data have demonstrated that a positive circumferential margin (i.e. microscopic tumour foci left behind laterally) is a very important prognostic marker for a local failure and for survival.4,5 Adequate lateral clearance is also a good marker of good surgery. However, even if surgery is performed correctly, some areas with microscopic tumour foci will not always be resected, even with a total mesorectal excision (TME). It has been proposed that those areas should be resected using an even more aggressive surgical strategy.6 This will substantially increase postoperative morbidity.7 On the other hand, these deposits are usually small and therefore easily eradicated by radiotherapy. The rationale for combining surgery and radiotherapy is obvious, since radiotherapy will eradicate tumour cells in the periphery where surgery cannot be radical without causing too much morbidity. Surgery
takes care of the tumour bulk, where radiotherapy will always fail owing to the presence of too many tumour cells. This requires that the additional radiotherapy can be given without significantly increasing morbidity.
