The aim of this study is to reduce the positive margin rate of 30% to around 15%. The study is an international multicentre, prospective, observational study, whereby patients with biopsy-proven low-rectal cancer (lower edge of the tumour < 6cms from the anal verge on MRI), will be recruited from participating centres, having given informed, written consent. Data from the radiology, surgical and pathological aspects will be collected and analysed centrally at the Royal Marsden Hospital. The patient's medical records will be reviewed for five years post surgery, and the patients will also be followed up by quality of life questionnaires. This project aims to show that in low rectal cancer, improved local control and survival can be achieved through a reduction in the involved CRM rates by MRI-planned surgery and selective pre-operative therapy. It also aims to assess the ability to predict disease recurrence and to provide an assessment of disease-free survival and overall survival.