[Quality for the data basis of evidence-based medicine: rectal cancer and preoperative 5 x 5 irradiation].

Annually 25,000 people are diagnosed with rectal cancer in Germany. Neoadjuvant short-term radiotherapy is recommended for advanced local disease and is able to reduce by half the local recurrence rates even under high quality surgical conditions. However, the prognosis is not affected by neoadjuvant short-term radiotherapy. Key problems of neoadjuvant short-term radiotherapy are late toxic effects including faecal incontinence, sexual dysfunction, gastrointestinal symptoms, cardiovascular diseases as well as an increased frequency of secondary malignancies. Therefore, any overstaging has to be avoided by using high quality pretreatment diagnostics. The prognosis is associated with the quality of surgery. Therefore, rectal cancer surgery should be performed in specialised centres only. In our opinion, there is presently no indication for short-term preoperative radiotherapy in rectal cancer due to its lack of influence on prognosis and the resulting late toxicities.