title: Ratio of metastatic lymph nodes is more important for rectal cancer patients treated with preoperative chemoradiotherapy.
abstract: OBJECTIVE
  To evaluate the predictive value of the lymph node (LN) ratio (LNR, number of metastatic LNs/ examined LNs) for recurrence in patients with rectal cancer and to compare its applicability according to preoperative chemoradiotherapy (PCRT).
  
  
  METHODS
  From 2000 to 2009, 967 patients with metastatic LNs after curative resection for locally advanced rectal cancer were identified. Patients were categorized according to PCRT (PCRT vs No PCRT). The cut-off LNR was determined based on the pN1 vs pN2 when the recommended number of LNs was harvested. The 5-year recurrence-free survival (RFS) rates using the Kaplan-Meier method were compared according to p/yp N stage and the LNR in each group.
  
  
  RESULTS
  Among patients with the same p/ypN stage, the 5-year RFS rate differed according to the LNR. In addition, the 5-year RFS rate was significantly different between pN and LNR groups in patients with No PCRT. In PCRT group, however, only LNR was associated with prognosis. On multivariate analysis, both pN and LNR were significant independent prognostic factors for 5-year RFS in the No PCRT group. In the PCRT group, only LNR category was found to be associated with RFS (HR = 2.36, 95%CI: 1.31-3.84, and P = 0.001).
  
  
  CONCLUSIONS
  The LNR is an important prognostic predictor of RFS in rectal cancer patients especially treated with PCRT. Current pN categories could not discriminate between prognostic groups of RFS after PCRT.
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: In Ja
authors: IJ
authors: Park
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Chang Sik
authors: CS
authors: Yu
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Seok-Byung
authors: SB
authors: Lim
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Yong Sik
authors: YS
authors: Yoon
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Chan Wook
authors: CW
authors: Kim
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Tae Won
authors: TW
authors: Kim
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Jong Hoon
authors: JH
authors: Kim
authors: In Ja Park, Chang Sik Yu, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jin Cheon Kim, Department of colon and rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul 138-736, South Korea.
authors: Jin Cheon
authors: JC
authors: Kim
mesh_terms: D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Lymph node ratio; Preoperative chemoradiotherapy; Prognosis; Rectal cancer; pN