title: Post-mastectomy radiotherapy can improve survival in breast cancer patients aged 35 years or younger with four or more positive nodes but not in one to three positive nodes.
abstract: BACKGROUND
  This retrospective study investigated the clinical value of post-mastectomy radiotherapy (PMRT) in female Chinese breast cancer patients aged 35 years or younger with positive axillary lymph nodes after mastectomy.
  
  
  METHODS
  We performed an analysis of clinical pathological data from 221 female Chinese breast cancer patients aged 35 years or younger treated between 1998 and 2007. Patients were diagnosed with positive axillary lymph nodes and underwent mastectomy. PMRT was delivered to 92 patients.
  
  
  RESULTS
  The median follow-up was 61 months. The 5-year locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were 84.1%, 65.2%, 61.4%, and 77.2%, respectively. Univariate survival analysis (P=0.003) and multivariate analysis (P<0.001) both suggested that PMRT is an independent prognostic factor of LRFS. PMRT positively affected LRFS (P=0.003), but had no significant impact on DMFS (P=0.429), DFS (P=0.146), and OS (P=0.750). PMRT improved LRFS (P=0.001), DFS (P=0.017), and OS (P=0.042) in patients with four or more positive nodes, but no survival benefit was observed in patients with one to three positive nodes (P>0.05).
  
  
  CONCLUSIONS
  PMRT can improve survival in breast cancer patients aged 35 years or younger with four or more positive nodes but not in those with one to three positive nodes.
authors.affiliation: Xiamen Cancer Center, Department of Radiation Oncology, the First Affiliated Hospital of Xiamen University, Xiamen, People's Republic of China.
authors.forename: Sangang
authors.initials: S
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, People's Republic of China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.affiliation: Xiamen Cancer Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Xiamen University, Xiamen, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, People's Republic of China.
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, People's Republic of China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Li
authors.affiliation: Xiamen Cancer Center, Department of Radiation Oncology, the First Affiliated Hospital of Xiamen University, Xiamen, People's Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, People's Republic of China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: He
keywords: breast cancer; locoregional recurrence; mastectomy; radiation therapy; young age