Determining the use of preoperative (chemo)radiotherapy in primary rectal cancer according to national and international guidelines

Background: Pre-operative radiotherapy (RT) or chemoradiotherapy (CRT) is frequently used prior to rectal cancer surgery to improve local control and survival. The treatment is administered according to guidelines, but these recommendations vary significantly between countries. Based on the stage distribution and risk factors of rectal cancers as determined by magnetic resonance imaging (MRI) in an unselected Swedish population, the use of RT/CRT according to 15 selected guidelines is described. Materials and methods: Selected guidelines from different countries and regions were applied to a wellcharacterized unselected population-based material of 686 primary non-metastatic rectal cancers staged by MRI. The fraction of patients assigned to surgery alone or surgery following pre-treatment with (C) RT was determined according to the respective guideline. RT/CRT administered to rectal cancer patients for other reasons, for example, for organ preservation or palliation, was not considered. Results: The fraction of patients with a clear recommendation for pre-treatment with (C) RT varied between 38% and 77% according to the different guidelines. In most guidelines, CRT was recommended to all patients who were not operated directly, and, in others, short-course RT was also recommended to patients with intermediate risk tumours. If only non-resectable or difficult to resect tumours were recommended pre-treatment, as stated in many Japanese publications, 9% would receive CRT followed by a delay to surgery. Conclusions: According to most guidelines, well over 50% of primary non-metastatic rectal cancer patients from a general population, in which screening for colorectal cancer is not practised, are recommended treatment with pre-operative/neo-adjuvant therapy. (C) 2019 Elsevier B. V. All rights reserved. Radiotherapy and Oncology