title: Preoperative Submucosal Injection of Carbon Nanoparticles Improves Lymph Node Staging Accuracy in Rectal Cancer after Neoadjuvant Chemoradiotherapy.
abstract: BACKGROUND
  The aim of this study was to evaluate the association between the number of nodes harvested and the rate of node positivity, and to evaluate the effect of carbon nanoparticles (CNPs) in improving lymph node detection and staging accuracy in patients who received neoadjuvant chemoradiotherapy (NCRT) followed by curative resection.
  
  
  METHODS
  Between September 2008 and June 2014, 152 consecutive rectal cancer patients treated with NCRT and curative resection were included. Forty-five patients underwent preoperative submucosal injection of CNPs (CNP group); the other patients underwent surgery only (control group). The relationship between the number of lymph nodes harvested and the rate of node positivity was investigated. A comparison of the number of harvested lymph nodes and the node positivity rate between the 2 groups was also performed. The lymph nodes in the CNP group were analyzed in detail.
  
  
  RESULTS
  The rate of node positivity increased gradually from 8.6% in patients with 1 to 5 nodes assessed to 37.8% in patients with 17 to 44 nodes assessed. The number of lymph nodes harvested was an independent risk factor for node positivity (p = 0.036). The mean number of lymph nodes retrieved in the CNP group was more than in the control group (21.1 vs 8.0, p = 0.000). The percentage of patients with positive lymph nodes was lower than in the control group (19.6% vs 35.6%, p = 0.037). In the CNP group, of 58 metastatic lymph nodes, 45 (77.6%) were dyed. Of 37 metastatic lymph nodes smaller than 5 mm, 33 (89.2%) were dyed.
  
  
  CONCLUSIONS
  More precise oncologic prognosis assessment was provided for patients with rectal cancer after NCRT by increasing the number of lymph nodes counted using a dye-tracing method, indicating that the use of CNPs is beneficial.
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Deng
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xue
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.affiliation: Department of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China. Electronic address: gzliguoxin@163.com.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Li
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D000328:Adult; D000368:Aged; D002244:Carbon / Q000008:administration & dosage*; D059186:Chemoradiotherapy, Adjuvant; D004396:Coloring Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007267:Injections; D007413:Intestinal Mucosa; D016015:Logistic Models; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000008:administration & dosage*; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011300:Preoperative Care / Q000379:methods*; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D012189:Retrospective Studies
chemical_list: D004396:Coloring Agents; D002244:Carbon