title: Ratio and log odds of positive lymph nodes in breast cancer patients with mastectomy.
abstract: OBJECTIVE
  This study aimed to investigate the predictive role of lymph nodes (LNs) and assess the prognostic significance of the ratio of positive LNs (LNR) and log odds of positive LNs (LODDS) in breast cancer patients who have undergone a mastectomy.
  
  
  METHODS
  All of the breast cancer patients in the Taiwan Cancer Database during 2002-2006 were considered. We excluded patients who had inflammatory breast cancer, stage 0 and IV disease, breast conservative surgery or survival <1 month. The primary end point was overall survival (OS). A Cox hazards model was constructed and compared via Nagelkerke R(2) (R(2)N) and receiver operating characteristics (ROC).
  
  
  RESULTS
  A total of 11,349 (6042 node-negative, 5307 node-positive) patients were enrolled, and 10.5% patients had a limited number of LNs harvested. In a multivariate Cox model, LNR and LODDS demonstrated prognostic significance (<0.001). For node-positive patients, a model with LNR showed the best fit (P < 0.001; R(2)N = 18.2%) when sufficient LNs were examined. However, a model with LODDS showed the best fit in patients with a limited number of LNs harvested (P < 0.001; R(2)N = 21.1%), even in node-negative patients (P = 0.004; R(2)N = 13.5%). The area under the ROC curve (AUC) was highest for LODDS (AUC: 0.761), followed by LNR (AUC: 0.757). A limited LN harvest induced an AUC value for an approximate 3.6% loss (LNR) or 3.1% loss (LODDS).
  
  
  CONCLUSIONS
  The prognostic superiority of LNR is confounded by a limited LN harvest, thus making LODDS the most powerful and unified prognostic classifier in breast cancer patients who have had a mastectomy.
authors.affiliation: Graduate Institute of Health Policy and Management, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Ophthalmology, Heping Branch, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Li-Ju
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Graduate Institute of Health Policy and Management, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Kuo-Piao
authors.initials: KP
authors.lastname: Chung
authors.affiliation: Department of Surgery, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Foundation, Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Yao-Jen
authors.initials: YJ
authors.lastname: Chang
authors.affiliation: Department of General Surgery, National Taiwan University Hospital, Taipei, Taiwan; Department of General Surgery, Zhongxing Branch, Taipei City Hospital, Taipei, Taiwan. Electronic address: yunjauchang2003@gmail.com.
authors.forename: Yun-Jau
authors.initials: YJ
authors.lastname: Chang
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008408:Mastectomy; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D013624:Taiwan
keywords: Breast cancer; Log odds of positive lymph nodes; Mastectomy; Ratio of positive lymph nodes; Survival analysis