Background
In the multimodal treatment of locally advanced rectal cancer, neoadjuvant chemoradiotherapy (nRCTX) has further decreased local recurrence rates but without a general survival benefit. In view of good local control by total mesorectal excision (TME), a prognostically very heterogeneous group of patients with T3 tumors, a limited preoperative lymph node staging and the establishment of magnetic resonance imaging (MRI)-based circumferential resection margins (CRM) as an important prognostic parameter, the indications for nRCTX should be more differentiated.
Material and methods
The main aspects of the indications for nRCTX of rectal cancer are discussed. Relevant studies were selected and further research based on the reference lists was undertaken.
Results
With adequate adherence to the quality of preoperative MRI diagnostics and TME surgery, patients with cT1/2 tumors in the middle/lower third of the rectum and questionable lymph node involvement and cT3 tumors in the middle third with MRI-based negative CRM (mrCRM >1 mm) and without any suspicion of lymph node metastases or extramural vascular invasion (EMVI negative), a primary resection without nRCTX can be carried out as an individual variation. The evidence for using mrCRM >1 mm as a sole selection parameter for primary surgery without nRCTX is insufficient.
Conclusion
With respect to the promising results of MRI-based indications for nRCTX depending on mrCRM, the results of controlled randomized trials are to be awaited. Thus, an application of this alternative concept should only be carried out following meticulous patient informed consent and reference to the standard of care laid down in guidelines.