Saving the rectum with watchful waiting after radiotherapy in early rectal cancer

Who can take part

• The subject has given their written consent to participate in the trial
• Be 18 years or older
• Have an adenocarcinoma verified tumour within the rectum below 12 cm from anal verge
• Have a tumour stage of TX/T1-3b (regardless of tumour size)
• Have no nodal metastases (NX/N0)
• Have no distant metastases (MX/M0)
• Have an Eastern Cooperative Oncology Group (ECOG) performance status 0-1
• For female subjects of childbearing potential: Have a negative pregnancy test within 7 days prior to study entry and Agree to use adequate, medically approved, contraceptive precautions from trial entry until 6 months after the end of study treatment
• If non-sterilised male with a partner of childbearing potential, must: Agree to use adequate, medically approved, contraceptive precautions from trial entry until 6 months after the end of study treatment

Who cannot take part

• Have no residual luminal tumour following endoscopic resection prior to first visit at surgical department
• Have contraindications to radiotherapy including previous pelvic radiotherapy
• Have uncontrolled cardiorespiratory comorbidity (includes patients with inadequately controlled angina or myocardial infarction or arrhythmia within 6 months prior to trial entry)
• Have been taking coumarin-derivative anticoagulants (e.g. warfarin) that cannot be discontinued at least 7 days prior to starting treatment or substituted by low molecular weight heparin
• Have known Gilbert’s disease (hyperbilirubinemia)
• Have history of severe and unexpected reactions to fluoropyrimidine therapy
• No biopsy confirmed rectal cancer (adenocarcinoma)
• Have a recurrent rectal cancer
• Have concomitant or previous malignancies within 3 years prior to trial entry, except those that in the opinion of the MDT are unlikely to relapse within 3 years or lead to death within 5 years
• Have unequivocal evidence of metastatic disease (includes respectable metastases)(Patients with equivocal radiological lesions (e.g. retroperitoneal, liver, lung) that are not classified as M1 are eligible if agreed by MDT)
• An age below 18
• Give no informed consent
• Have known complete dihydropyrimidine dehydrogenase (DPYD) deficiency
• Are taking metronidazole, phenytoin or sorivudine or its chemically related analogues, such as brivudine, within 4 weeks of trial entry (see Section 8.3.5 for further details)
• Are Pregnant or lactating woman
• Have an MRI node positive tumour (≥N1, defined by protocol guidelines) (Patients with equivocal radiological findings that are either classified as NX or N0 are eligible)
• Have MRI extramural vascular invasion (mriEMVI) positive (defined by protocol guidelines)
• Have a threatened mesorectal fascia (≤1 mm on MRI or ERUS)