Watch-and-wait approach versus surgical resection after chemoradiotherapy for patients with rectal cancer (the OnCoRe project): a propensity-score matched cohort analysis,Lancet Oncol Published Online December 16, 2015,2004.10 ,Annals of Surgery,Habr-Gama.eg 265 patients with distal rectal were treated by CRT with 5-FU, Leucovorin and 5040 cGy Five-year OS and DFS rates were 88% and 83% in Resection Group ,100% and 92% in Observation Group,Purpose,oncological outcomes between watch and wait and surgical resection the safety of the watch-and-wait,The definition of a cCR,(1) substantial downsizing with no residual tumor or residual fibrosis only (2) no suspicious lymph nodes on MRI (3) no residual tumor at endoscopy or only a small residual erythematous ulcer or scar (4) negative biopsies from the scar, ulcer, or former tumor location (5) no palpable tumor, when initially palpable with digital rectal examination,Methods,one-to-one paired cohorts of watch and wait versus surgical resection using propensity-score matching（ T stage, age, and performance status） primary endpoint was DFS secondary endpoints was OS and colostomy-free survival,Methods,CCR standard: after CRT 8 weeks or more absence of residual ulceration, stenosis, or mass within the rectum during digital rectal examination and endoscopic examination,Methods,259 patients from a tertiary cancer centre in Manchester, UK between Jan 14, 2011 and April 15, 2013 CCR-wait-and-see policy group(31) NCCR-surgical resection(228),Methods,three neighbouring UK regional cancer centres(Lancashire and South Cumbria, Merseyside and Cheshire, and north Wales) March 10, 2005, and Jan 21, 2015- wait-and-see policy group(98),Methods,preoperative chemoradiotherapy:45 Gy in 25 daily fractions with concurrent fluoropyrimidine-based chemotherapy for 34 days,Methods,Data include: T and N stages (MRI) Sex, age, BMI Smoking status, performance status Baseline CEA Histological grade Height from anal verge,Methods,Statistical analysis continuous variables-Kruskal-Wallis and Wilcoxon signed-rank tests categorical variables- and McNamara tests P value,Results,Median follow-up of 33 months (IQR 1943) 44/129 patients had local regrowths(42 patients had mucosal lesions,2 patient had submucosal or mesorectal lesions),Results,Results,31 underwent subsequent salvage surgery T and N stages 5 ypT1, 10 ypT2, 16 ypT3 24 ypN0, 6 ypN1, 1 ypN2,Results,Results,Results,Discussion,a new oncological endpoint-non-regrowth disease-free survival the first time- colostomy-free survival(1/4 CCR avoid colostomy),Discussion,Two additional finding about 2/3 node positive assessed by MRI, but did not affect subsequent endpoints 9% (CCR) did not receive preoperative chemotherapy and its absence did not affect study endpoints,Discussion,limitations 1. follow-up was relatively short 2.not representative of real-world off -trial clinical practice 3. is a risk in patients with CCR managed by watch and wait,Discussion,Strengths 1.largest reported cohort outside 2. from several treatment centres 3. a standardised defi nitionCCR,Future Perspectives,Need a prospective randomized controlled trial uniform standards for the definition of a cCR The proposed selection criteria and follow-up can be used in future trials aimed at providing more evidence on the wait-and-see policy,