This research is being done as part of a larger international database for 'Watch and Wait' rectal cancer patients. Currently, the 'Watch and Wait' treatment shows promising results worldwide, however further research of long-term results is needed. Therefore, this research will contribute to the evaluation of the long-term results of this treatment as part of the Internal Watch and Wait Database an international project initiated by the Champalimaud Foundation and European Registry of Cancer Care (EURECCA).