title: Wait and see approach for rectal cancer with a clinically complete response after neoadjuvant concurrent chemoradiotherapy.
abstract: OBJECTIVE
  Rectal cancer patients with a pathological complete response (pCR) after neoadjuvant concurrent chemoradiotherapy (CCRT) have a better prognosis compared to those without a pCR. Therefore, the "Wait and See" (W&S) approach in those who achieved clinically complete response (cCR) after CCRT was introduced as an alternative modality to the total mesorectal excision (TME). The aim of this study was to compare the oncological outcomes between W&S and TME via meta-analysis.
  
  
  METHODS
  We performed a comprehensive literature search on January 14, 2016, using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. In addition, the references of all articles obtained were searched manually. The qualities of each study were assessed using the Newcastle-Ottawa quality assessment scale. The main outcomes were recurrence, disease-free survival (DFS), and overall survival (OS). We calculated the risk ratio (RR) and hazard ratio (HR) for the recurrence and survival rates, respectively.
  
  
  RESULTS
  The RR of patients whose initial recurrences was local recurrence (LR), distant metastasis (DM), LR + DM, or overall recurrences were 0.18, 1.00, 0.61, and 0.49, respectively. There was no heterogeneity in the results. The HR of DFS was 0.59 and indicated that DFS in the TME group was superior compared with that in the W&S group. The OS has no significant difference between the studies.
  
  
  CONCLUSIONS
  Although the W&S approach seemed feasible for rectal cancer patients with a cCR after neoadjuvant CCRT, concrete evidence obtained in well-controlled randomized trials with a long-term follow-up is required to validate potential treatment options.
authors.affiliation: Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.|Institute of Evidence-based Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.|Institute of Health Science, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Song
authors.affiliation: Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.|Institute of Evidence-based Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Hyeong Sik
authors.initials: HS
authors.lastname: Ahn
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors.forename: Bong-Hoi
authors.initials: BH
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.|Institute of Health Science, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Hojin
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors.forename: Hoon Sik
authors.initials: HS
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.|Institute of Health Science, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Yun Hee
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.|Institute of Health Science, Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: Ki Mun
authors.initials: KM
authors.lastname: Kang
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea. blue129j@gnu.ac.kr.|Institute of Health Science, Gyeongsang National University, Jinju, Republic of Korea. blue129j@gnu.ac.kr.
authors.forename: Bae Kwon
authors.initials: BK
authors.lastname: Jeong
mesh_terms: D059248:Chemoradiotherapy; D006801:Humans; D020360:Neoadjuvant Therapy; D012004:Rectal Neoplasms / Q000601:surgery / Q000628:therapy*; D012007:Rectum / Q000601:surgery; D016896:Treatment Outcome; D057832:Watchful Waiting
keywords: Chemoradiotherapy; Mesorectal excision; Overall survival; Rectal cancer; Salvage therapy; Wait and see