title: The effects of ECE on the benefits of PMRT for breast cancer patients with positive axillary nodes.
abstract: BACKGROUND
  The purpose of the present study was to retrospectively evaluate the effects of extracapsular extension (ECE) on the benefits of post-mastectomy radiation therapy (PMRT) for groups of patients with varying numbers of positive axillary nodes (1-3, 4-9 and ≥10 positive axillary nodes).
  
  
  METHODS
  A total of 1220 axillary node-positive patients who had received mastectomy were involved in this study. Patients were grouped as 'Radio + /ECE + ', 'Radio-/ECE + ', 'Radio + /ECE-' or 'Radio-/ECE-' according to status of ECE and whether receiving PMRT or not, and were evaluated in terms of local region relapse (LRR) rate. The 5-year and 10-year Kaplan-Meier disease-free survival and overall survival (OS) rates were analyzed.
  
  
  RESULTS
  ECE-positive differed from ECE-negative groups with statistical significance for all comparisons in favor of the ECE-negative group: 5-year locoregional failure-free survival (LRFFS) (82.69% vs 91.83%, P < 0.001), 10-year LRFFS (75.39% vs 90.02%, P < 0.001); 5-year OS (52.12% vs 74.46%, P < 0.001), 10-year OS (35.17% vs 67.63%, P < 0.001). There were no significant effects of ECE on the benefits of PMRT for patients with 1-3 (P = 0.5720), ≥10(P = 0.0614) positive axillary nodes. However, for the group of patients with 4-9 positive axillary nodes, ECE status had a significant effect on the benefits of PMRT with respect to 5-year and 10-year LRFFS (P < 0.05).
  
  
  CONCLUSIONS
  In our study, regardless of the ECE status, PMRT didn't significantly improve the LRFFS for patients with 1-3 or ≥10 positive axillary nodes. However, for patients with 4-9 positive axillary nodes, ECE could be an important criterion to consider when deciding whether to receive PMRT.
authors: The First Surgical Department of Breast Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy, Huanhu West Road, Hexi District, Tianjin 300060, China.
authors: Wenwen
authors: W
authors: Geng
authors: Bin
authors: B
authors: Zhang
authors: Danhua
authors: D
authors: Li
authors: Xinrui
authors: X
authors: Liang
authors: Xunchen
authors: X
authors: Cao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001365:Axilla / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects*; D008207:Lymphatic Metastasis / Q000532:radiotherapy*; D008875:Middle Aged; D015233:Models, Statistical; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D011878:Radiotherapy / Q000379:methods*; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: ECE; PMRT; breast neoplasms; prognosis
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