{"entity":{"id":"clinical-complete-response","kind":"term","name":"Clinical complete response (cCR)","aka":[],"tldr":"No sign of tumour on examination, endoscopy, and MRI after treatment, without surgery to confirm it. It is the basis of organ-preservation strategies.","summary":"Defined by digital rectal exam, endoscopy (flat white scar), and MRI (TRG1) in rectal cancer; sustained cCR at 12 months is the primary endpoint of AZUR-1. Watch-and-wait after chemoradiation (OPRA, IWWD) and after immunotherapy (dostarlimab) preserve the rectum; regrowth is usually salvageable with surgery.","asOf":"2026-09-07","wikipedia":"https://en.wikipedia.org/wiki/Watchful_waiting","links":[{"label":"ClinicalTrials.gov NCT05723562: AZUR-1","url":"https://clinicaltrials.gov/study/NCT05723562"},{"label":"ClinicalTrials.gov NCT05953181: SANO","url":"https://clinicaltrials.gov/study/NCT05953181"},{"label":"van der Valk, Lancet 2018: long-term outcomes of clinical complete responders in the International Watch and Wait Database (880 patients)","url":"https://doi.org/10.1016/s0140-6736(18)31078-x"},{"label":"Verheij, J Clin Oncol 2024: long-term results of the OPRA trial (median follow-up 5.1 years)","url":"https://doi.org/10.1200/jco.23.01208"}],"tags":[],"related":[],"cancers":["colorectal","esophageal"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["pcr","watch-and-wait-rectal-cancer","organ-preservation"],"trials":["azur-1","sano"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["What happens to people who keep the rectum: in 880 patients in the International Watch and Wait Database, local regrowth reached 25.2 percent at two years, 88 percent of regrowths appeared within two years and 97 percent were in the bowel wall, where salvage surgery is still possible; five-year overall survival was 85 percent and disease-specific survival 94 percent (van der Valk 2018). In the OPRA trial at a median of 5.1 years, disease-free survival was the same (64 percent) whether the rectum was removed after restaging or after a regrowth (2024)."],"category":"Endpoints"},"route":"/terms/clinical-complete-response/","neighbours":{"cancer":[{"id":"anal","kind":"cancer","name":"Anal cancer (squamous cell carcinoma)","route":"/cancers/anal/"},{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"localised-anal-cancer","kind":"cancer","name":"Localised anal squamous cell carcinoma (stage I to III)","route":"/cancers/localised-anal-cancer/"},{"id":"msi-high-colorectal","kind":"cancer","name":"Mismatch-repair deficient (MSI-high) colorectal cancer","route":"/cancers/msi-high-colorectal/"},{"id":"esophageal","kind":"cancer","name":"Oesophageal cancer","route":"/cancers/esophageal/"},{"id":"rectal-cancer","kind":"cancer","name":"Rectal cancer","route":"/cancers/rectal-cancer/"}],"term":[{"id":"colorectal-trials-open-today","kind":"term","name":"Colorectal cancer trials open today (registry snapshot)","route":"/terms/colorectal-trials-open-today/"},{"id":"organ-preservation","kind":"term","name":"Organ preservation (watch-and-wait, bladder-sparing, larynx preservation)","route":"/terms/organ-preservation/"},{"id":"pcr","kind":"term","name":"Pathologic complete response (pCR)","route":"/terms/pcr/"},{"id":"watch-and-wait-rectal-cancer","kind":"term","name":"Watch and wait after chemoradiotherapy for rectal cancer","route":"/terms/watch-and-wait-rectal-cancer/"}],"trial":[{"id":"azur-1","kind":"trial","name":"AZUR-1","route":"/trials/azur-1/"},{"id":"cao-aro-aio-12","kind":"trial","name":"CAO/ARO/AIO-12","route":"/trials/cao-aro-aio-12/"},{"id":"iwwd","kind":"trial","name":"International Watch & Wait Database","route":"/trials/iwwd/"},{"id":"opra","kind":"trial","name":"OPRA","route":"/trials/opra/"},{"id":"sano","kind":"trial","name":"SANO","route":"/trials/sano/"},{"id":"star-trec","kind":"trial","name":"STAR-TREC","route":"/trials/star-trec/"}],"pairing":[{"id":"cross-then-nivolumab","kind":"pairing","name":"CROSS chemoradiation → surgery → adjuvant nivolumab if residual disease","route":"/pairings/cross-then-nivolumab/"},{"id":"neoadjuvant-io-dmmr","kind":"pairing","name":"Neoadjuvant checkpoint inhibitor → surgery (or no surgery) in dMMR colorectal cancer","route":"/pairings/neoadjuvant-io-dmmr/"}],"idea":[{"id":"idea-organ-preservation-esophageal","kind":"idea","name":"Organ preservation as the default after complete response in oesophageal cancer","route":"/ideas/idea-organ-preservation-esophageal/"},{"id":"idea-crc-organ-preservation-randomised-in-pmmr-rectal","kind":"idea","name":"Randomise organ preservation against surgery in mismatch repair-proficient rectal cancer, with bowel function as a co-primary endpoint","route":"/ideas/idea-crc-organ-preservation-randomised-in-pmmr-rectal/"}],"paper":[{"id":"paper-cercek-nonoperative-management-mismatch-repair-deficient-tumours-nejm-2025","kind":"paper","name":"Nonoperative management of mismatch repair-deficient tumors","route":"/key-papers/paper-cercek-nonoperative-management-mismatch-repair-deficient-tumours-nejm-2025/"},{"id":"paper-habr-gama-nonoperative-stage-0-rectal-ann-surg-2004","kind":"paper","name":"Operative versus nonoperative treatment for stage 0 distal rectal cancer following chemoradiation therapy: long-term results","route":"/key-papers/paper-habr-gama-nonoperative-stage-0-rectal-ann-surg-2004/"},{"id":"paper-garcia-aguilar-opra-organ-preservation-jco-2022","kind":"paper","name":"Organ preservation in patients with rectal adenocarcinoma treated with total neoadjuvant therapy (OPRA)","route":"/key-papers/paper-garcia-aguilar-opra-organ-preservation-jco-2022/"}],"roadmap":[{"id":"colorectal-roadmap","kind":"roadmap","name":"Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation","route":"/roadmaps/colorectal-roadmap/"}]}}