Tumour location and the effects of preoperative radiotherapy in the treatment of rectal cancer

Preoperative radiotherapy improves local control and survival in rectal can cer, but may also increase postoperative morbidity and mortality rates. Est ablishing selection criteria for preoperative radiotherapy is crucial. The tumour level above the anus may be one such criterion. The effect of preope rative radiotherapy in relation to the distance between the tumour and the anus was therefore assessed. In 457 patients operated for cure included in the Stockholm II Trial the lo cal recurrence rate in irradiated and non-irradiated patients was analysed in relation to the tumour location (low, mid or upper rectum). Radiotherapy reduced the local recurrence rate from 30 to 20 per cent in lo w rectal cancer, from 25 to 11 per cent in mid rectal cancer and from 21 to 5 per cent for tumours in the upper rectum. With conventional surgical techniques preoperative radiotherapy plays an im portant role in rectal cancer irrespective of the location of the tumour. T o irradiate only patients with tumours in the lower rectum and to omit this treatment for patients with tumours in the mid and upper rectum cannot be recommended. Whether this statement is valid with standardized total mesore ctal excision (TME) surgery is not known. Until this knowledge is available the current indications for preoperative radiotherapy should probably also be used with TME surgery.