[Neoadjuvant and surgical treatment for rectal cancer]. / Neoadjuvante und operative Therapie des Rektumkarzinoms.

According to the 2008 guidelines on colorectal cancer, whether preoperative therapy is indicated for rectal cancer should be judged based on the T and N categories. A few centres limit the indication for preoperative radio(chemo)therapy to patients with tumours that, according to magnetic resonance tomography (MRT), extend to the fascia mesorectalis or are 1 mm or less away from it - so-called circumferential resection margin-positive or CRM-positive tumours. Omitting preoperative therapy for MRT CRM-negative tumours is, however, a matter that still requires further study in clinical trials. The high rate of distant metastases continues to be a problem. Assuming that pathohistological complete remission (pCR) is a predictive marker of long-term disease-free survival after neoadjuvant radiochemotherapy, attempts are now being undertaken to intensify the neoadjuvant therapy. Phase II trials show improved pCR rates by combining the preoperative radiation with the double combinations oxaliplatin or irinotecan plus infusional or oral 5-FU (capecitabine). In the case of limited T1 rectal cancer without further risk factors, transanal local excision can be used.