title: Number of negative lymph nodes is associated with disease-free survival in patients with breast cancer.
abstract: BACKGROUND
  The aim of this study was to evaluate the prognostic value of the number of negative lymph nodes (NLNs) in breast cancer patients after mastectomy.
  
  
  METHODS
  2,455 breast cancer patients who received a mastectomy between January 1998 and December 2007 were retrospectively reviewed. The prognostic impact of the number of NLNs with respect to disease-free survival (DFS) was analyzed.
  
  
  RESULTS
  The median follow-up time was 62.0 months, and the 5-year and 10-year DFS was 87.1% and 74.3%, respectively. The DFS of patients with >10 NLNs was significantly higher than that of patents with ≤10 NLNs, and the 5-year DFS rates were 87.5% and 69.5%, respectively (P < 0.001). Univariate Cox analysis showed that the NLN count (continuous variable) was a prognostic factor of DFS (hazard ratio [HR] = 0.913, 95% confidence interval [CI]: 0.896-0.930, P < 0.001). In multivariate Cox analysis, patients with a higher number of NLNs had a better DFS (HR = 0.977, 95% CI: 0.958-0.997, P = 0.022). Subgroup analysis showed that the NLN count had a prognostic value in patients at different pT stages and pN positive patients (log-rank P < 0.001). However, it had no prognostic value in pN0 patients (log-rank P = 0.684).
  
  
  CONCLUSIONS
  The number of NLNs is an independent prognostic factor of DFS in breast cancer patients after mastectomy, and patients with a higher number of NLNs have a better DFS.
authors.affiliation: Xiamen Cancer Center, Department of Radiation Oncology, the First Affiliated Hospital of Xiamen University, Xiamen, 361003, People's Republic of China. unowu12345@hotmail.com.
authors.forename: San-Gang
authors.initials: SG
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 510060, People's Republic of China. sunjy@sysucc.org.cn.
authors.forename: Jia-Yuan
authors.initials: JY
authors.lastname: Sun
authors.affiliation: Xiamen Cancer Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Xiamen University, Xiamen, 361003, People's Republic of China. juanzhou12345@hotmail.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 510060, People's Republic of China. lify@sysucc.org.cn.
authors.forename: Feng-Yan
authors.initials: FY
authors.lastname: Li
authors.affiliation: Xiamen Cancer Center, Department of Radiation Oncology, the First Affiliated Hospital of Xiamen University, Xiamen, 361003, People's Republic of China. linqinxmfh@126.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 510060, People's Republic of China. linhx@sysucc.org.cn.
authors.forename: Huan-Xin
authors.initials: HX
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 510060, People's Republic of China. guanxh@sysucc.org.cn.
authors.forename: Xun-Xing
authors.initials: XX
authors.lastname: Guan
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 510060, People's Republic of China. hezhy@sysucc.org.cn.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: He
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008408:Mastectomy; D008593:Menopause; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor