title: Factors affecting number of lymph nodes harvested and the impact of examining a minimum of 12 lymph nodes in stage I-III colorectal cancer patients: a retrospective single institution cohort study of 1167 consecutive patients.
abstract: BACKGROUND
  To identify factors affecting the harvest of lymph nodes (LNs) and to investigate the association between examining a minimum of 12 LNs and clinical outcomes in stage I-III colorectal cancer (CRC) patients.
  
  
  METHODS
  The clinicopathologic features and the number of examined LNs for 1167 stage I-III CRC patients were analyzed to identify factors affecting the number of LNs harvested and the correlations between clinical outcomes and high harvests (≧12 LNs) and low harvests (<12 LNs).
  
  
  RESULTS
  A multivariate analysis showed that age (P = 0.007), tumor size (P = 0.030), and higher T stage (P = 0.001) were independent factors affecting the examinations of LNs in colon cancer and that tumor size (P = 0.015) was the only independent factor in rectal cancer. Patients with low harvests had poorer overall survival with stage II and stage III CRC (stage II: P < 0.0001; III: P = 0.001) and poorer disease-free survival for stages I-III (stage I: P = 0.023; II: P < 0.0001; III: P = 0.001).
  
  
  CONCLUSIONS
  The factors influencing nodal harvest are multifactorial, and an adequate number of examined LNs (≧12) is associated with a survival benefit. Removal of at least 12 LNs will determine the lymph node status reliably.
authors.affiliation: Division of Gastroenterology and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Surgery, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Hsiang-Lin
authors.initials: HL
authors.lastname: Tsai
authors.affiliation: Division of Gastroenterology and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Colorectal Surgery, Department of Surgery, KaohsiungMedical University Hospital, Kaohsiung, Taiwan.
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Huang
authors.affiliation: Division of Gastroenterology and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Trauma, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yung-Sung
authors.initials: YS
authors.lastname: Yeh
authors.affiliation: Division of Gastroenterology and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Colorectal Surgery, Department of Surgery, KaohsiungMedical University Hospital, Kaohsiung, Taiwan.|Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Cheng-Jen
authors.initials: CJ
authors.lastname: Ma
authors.affiliation: Department of Surgery, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Trauma, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Emergency Medicine, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chao-Wen
authors.initials: CW
authors.lastname: Chen
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Internal Medicine, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lu
authors.affiliation: Department of Radiation Oncology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Radiation Oncology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ming-Yii
authors.initials: MY
authors.lastname: Huang
authors.affiliation: Department of Nursing, Shu-Zen College of Medicine and Management, Kaohsiung, Taiwan.
authors.forename: I-Ping
authors.initials: IP
authors.lastname: Yang
authors.affiliation: Division of Gastroenterology and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.|Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.|Department of Surgery, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.|Division of Colorectal Surgery, Department of Surgery, KaohsiungMedical University Hospital, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.|Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.|Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, Kaohsiung, Taiwan. cy614112@ms14.hinet.net.
authors.forename: Jaw-Yuan
authors.initials: JY
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies
keywords: Colorectal cancer; Disease-free survival; Impact of examining lymph nodes; Lymph nodes harvested; Overall survival