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Copyright ©The Author(s) 2015.
World J Gastrointest Surg. Nov 27, 2015; 7(11): 306-312
Published online Nov 27, 2015. doi: 10.4240/wjgs.v7.i11.306
Table 2 Studies evaluating the watch and wait protocol
StudyPatients (n)Neoadjuvant therapy
DetailsOutcomes/endpoints
RadiationChemotherapy
Prospective
Habr-Gama et al[24] (Brazil)6954 Gy radiation (45-Gy delivered as 3-field approach with daily doses of 1.8 Gy on weekdays to pelvis, followed by 9-Gy boost to the primary tumor and perirectal tissue)3 cycles of 5-FU (450 mg/m2) bolus and a fixed dose of 50 mg leucovorin for 3 consecutive days every 3 wk. After completion of radiation, patients received 3 additional identical cycles of chemotherapy every 3 moAssessment after CRT: 10 wk; assessment for sustained cCR: From 10 wk to 12 mo after CRT; patients with local recurrences after sustained cCR classified as LR3-yr OS for patients with initial cCR = 3-yr DFS for patients with initial cCR = 72%
Lambregts et al[25] and Maas et al[26] (Netherlands)2128 fractions of 1.8 Gy = 50.4 GyIV oxaliplatin and capecitabineAssessment after CRT: 6-8 wk; evaluation for cCR: MRI and endoscopy; operative management with CRT and resection (control group): 20 patients with pCR after surgeryNonoperative management group; 1 patient developed LR and had surgery as salvage treatment; 20 patients are alive without disease; no difference in 2-yr DFS and OS between the watch and wait and the CRT and resection groups
Smith et al[27] (United States)32External beam radiation over 5-6 wk, median dose 50.4 Gy (range 45-56 Gy)5-FU or capecitabineAssessment after CRT: 4-10 wk; evaluation for cCR: DRE, endoscopy ± biopsy; evaluation for cCR at 1-yr: DRE, flexible sigmoidoscopy every 3 mo; evaluation for cCR subsequent years: DRE, flexible sigmoidoscopy every 4-6 mo; operative management (control group): 256 patients, 57 (22%) with pCR; median follow up: 28 moNonoperative management group had a higher rate of LR (21% vs 0%, P = 0.001): 6 recurred locally (median 11 mo), 3 had concurrent DR; 2-yr DR (8% vs 2%, P = 0.30), DFS (88% vs 98%, P = 0.27), and OS (97% vs 100%, P = 0.56) were similar for nonoperative management and rectal resection/pCR groups
Dalton et al[28] (United Kingdom)1245 Gy in 25 fractions over 5 wkConcurrent capecitabineAssessment after CRT: 8 wk; evaluation for cCR: MRI complemented with EUA/biopsy and PET/CT if tumor regression is suspected; cCR patients are followed with repeat EUA at 3 mo and 12 mo, and 6-monthly PET/CT and MRI; median follow up 25.5 mocCR in 12/49 (24.4%); 6/12 patients with cCR without evidence of disease