Individualizing treatment for locally advanced rectal cancer

Abstract

Based on results of the German Rectal Cancer Study Group CAO/ARO/AIO-94 trial, long-term chemoradiotherapy (RT/CTx) is recommended as standard treatment for locally advanced rectal cancer (UICC stages II/III) in the lower two thirds of the rectum (0-12 cm from the anocutaneous verge). Tumor response to neoadjuvant therapy is very heterogeneous, ranging from complete remission to total resistance to RT/CTx. To fulfill the clinical requirement of individual and risk-adapted multimodal treatment, distinct progress in translational research has been achieved (e.g. gene profiling). However, in clinical reality "individualization" of the therapy of rectal cancer patients has not actually been realized. This can be achieved only on the basis of successful randomized clinical trials (e.g. the CAO/ARO/AIO-04 and GAST-05 trials) translationally combined with basic scientific approaches. One simple first step toward individualizing rectal cancer therapy is being made with the ongoing GAST-05 trial. This investigator initiated phase II trial funded by the German Research Foundation (Deutsche Forschungsgemeinschaft) excludes preoperative RT/CTx for patients with rectal cancer localized in the upper third of the rectum, using only quality controlled principles of radical surgery (partial vs total mesorectal excision) followed by adjuvant chemotherapy.