title: [Correlations between DNA mismatch repair (MMR) and prognosis and prediction of treatment efficacy in stage II/II colon cancer].
abstract: OBJECTIVE
  To investigate the role of DNA mismatch repair (MMR) as a prognostic indicator of radical resection and a predictor of fluorouracil-based adjuvant therapy benefit in patients with stage II/III colon cancer.
  
  
  METHODS
  The clinicopathological characteristics of 172 patients with stage II/III colon cancer who underwent radical resection were retrospectively analyzed. Immunohistochemical staining was used to detect the expression of DNA mismatch repair (MLH1/MSH2/MSH6/PMS2) in the tumor tissues.
  
  
  RESULTS
  Among a total of 172 patients, there were 38 (22.1%) cases with defective DNA mismatch repair (dMMR) and 134 (77.9%) cases with proficient DNA mismatch repair (pMMR). Among the 115 patients who did not receive adjuvant chemotherapy, those with tumor displaying dMMR had a better 5-year overall survival (OS) rate and disease-free survival (DFS) rate than the patients with proficient DNA mismatch repair (pMMR) (88.0% vs. 66.7%, P = 0.040; 84.0% vs. 60.0%, P = 0.034). The benefit of adjuvant chemotherapy differed significantly according to the MMR status. Adjuvant 5-Fu chemotherapy improved the 5-year overall survival rate among 134 patients with pMMR (86.4%) than that in patients treated by surgery alone (66.7%, P = 0.012). By contrast, there was no benefit of adjuvant 5-Fu chemotherapy in the patients with dMMR (61.5% vs. 86.4%, P = 0.062), which was even more clear the 5-year disease-free survival rate (53.8% vs. 84.0%, P = 0.038).
  
  
  CONCLUSIONS
  MMR status is a predictor of the benefit of adjuvant chemotherapy with fluorouracil in stage II/III colon cancer. Patients with stage II/III colon cancer displaying dMMR have a better prognosis than those with pMMR.
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Qin
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Jianming
authors.initials: J
authors.lastname: Ying
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Lyu
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Wenxue
authors.initials: W
authors.lastname: Zhi
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China. Email: zhouap1825@126.com.
authors.forename: Aiping
authors.initials: A
authors.lastname: Zhou
authors.affiliation: Department of Oncology, Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
authors.forename: Jinwan
authors.initials: J
authors.lastname: Wang
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000628:therapy; D003131:Combined Modality Therapy; D053843:DNA Mismatch Repair; D018572:Disease-Free Survival; D005472:Fluorouracil; D006801:Humans; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D005472:Fluorouracil