title: A nomogram to predict distant metastasis after neoadjuvant chemoradiotherapy and radical surgery in patients with locally advanced rectal cancer.
abstract: OBJECTIVE
  To compare distant metastasis (DM) in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and surgery alone, and to develop a predictive nomogram for DM following nCRT.
  
  
  METHODS
  Propensity-scoring match analysis was performed to compare DM in LARC treated with nCRT (n = 375) and surgery alone (n = 375). Cox regression was performed to identify predictors of DM following nCRT. A nomogram was developed and validated by internal (n = 425) and external validation (n = 97).
  
  
  RESULTS
  The 5-year local recurrence rate was significantly lower in the nCRT group (5.6% vs. 10.4%; P = 0.020). The 5-year DM rates (nCRT vs. surgery alone: 25.3% vs. 24.4%; P = 0.235) were similar between groups. Cox regression showed that the post-nCRT pathologic stage (ypTNM stage, OR = 2.022, P = 0.002), IMA nodal metastasis (OR = 2.171, P = 0.023), and CRM involvement (OR = 2.535, P = 0.016) were independently associated with DM following nCRT. A predictive nomogram was developed with a C-index of 0.70 on internal validation, and 0.71 on the external validation.
  
  
  CONCLUSIONS
  NCRT improved local control, but not distant metastasis. A nomogram to predict 3- and 5-year DM rates, using clinicopathological parameters, was successfully developed. This prognostic tool could support decision-making in clinical practice and follow-up strategies.
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Huiming
authors.initials: H
authors.lastname: Lin
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Xingrong
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Zongbin
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Huang
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, People's Republic of China.
authors.forename: Pan
authors.initials: P
authors.lastname: Chi
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000628:therapy*; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D006801:Humans; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D049451:Nomograms; D057216:Propensity Score; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D012189:Retrospective Studies
keywords: chemoradiotherapy; neoplasm metastasis; nomogram; rectal cancer