Limitation of surgical radicality in rectal cancer responding to neoadjuvant therapy.

The basic principle in the treatment of rectal cancer is the complete surgical removal of the tumor together with the lymphatic drainage region, i.e. the mesorectum encased by the mesorectal 'fascia pelvis visceralis' according to Westhues. It was shown in the 1990s that the results of surgery alone could be improved by additional adjuvant and neoadjuvant therapy. Because of less toxicity and a lower rate of local recurrence, neoadjuvant therapies in International Union Against Cancer (UICC) stage II and III disease are now preferred over adjuvant strategies. The German Rectal Cancer study CAO/ARO/AIO-94 showed a full remission rate of 8% after a 5-fluorouracil (5-FU)based chemotherapy added to a conventional fractional radiation therapy (50.4 Gy). This figure, together with similar results of others, leads to the question whether surgical radicality in rectal cancer treatment could be limited in case of a good remission after neoadjuvant therapy. There are several promising possibilities under investigation, e.g. local excision instead of radical resection, or even no resection at all. Nevertheless, up to now these strategies did not prove to give comparable results to standard surgical procedures. Therefore, reduction of radicality in curable rectal cancer should be limited to accurately designed randomized clinical trials.