Clinical Research Directory

Inclusion Criteria: * Aged 18 years or older * Primary rectal cancer (pathologically confirmed) * Treated with neoadjuvant (chemo)radiotherapy * Clinical complete response (ycT0N0) to neoadjuvant treatment, as determined clinically (digital rectal examination, endoscopy) and radiologically (diffusion weighted imaging-MRI). * Informed consent and capability of giving informed consent; before informed consent is obtained the patient will be extensively informed about the fact that 'wait-and-see' instead of conventional surgery is not accepted yet by most physicians and that the risks and benefits from these strategies have not been fully determined yet. These issues will be discussed in the patient information form as well. * Comprehension of the alternative strategies and risks are clear to the patient (in other words that the patient understands the experimental base of the study). Exclusion Criteria: * Recurrent rectal cancer * Contra-indications for MRI. If MRI is not possible because of contra-indications (e.g. pacemaker) patients will be excluded. MRI is crucial for response evaluation and follow-up and cannot be omitted in patients that follow the 'wait-and-see policy'. * Unable to understand or read Dutch * Unable or unwilling to comply to the intensive follow-up schedule