title: Clinical outcomes according to molecular subtypes in stage II-III breast cancer patients treated with neoadjuvant chemotherapy followed by surgery and radiotherapy.
abstract: OBJECTIVE
  We evaluated the tumor response and clinical outcomes according to molecular subtypes in stage II-III breast cancer patients who received neo-adjuvant chemotherapy (NAC) followed by surgery and radiotherapy.
  
  
  METHODS
  We retrospectively analyzed 329 patients with clinical stage II-III breast cancer who received NAC followed by surgery and radiotherapy. Luminal A and B, HER2-enriched and triple-negative subgroups were identified.
  
  
  RESULTS
  The overall pathologic complete response (pCR) rate after NAC was 20.1% and the HER2-enriched subgroup had the highest pCR rate (43.6%), whereas luminal A showed the lowest rate of pCR (4.6%). The median follow-up duration was 55 months (range, 5-98 months). The 5-year overall survival (OS) and disease-free survival (DFS) rates were 88.9% and 72.9%, respectively. In subgroup analysis, according to the pathologic response (pCR vs non-pCR), the triple-negative subtype exhibited a significant difference in 5-year OS rate (100.0% vs 71.6%, P = 0.005) and 5-year DFS rate (93.1% vs 55.1%, P < 0.001). A distinct survival difference according to molecular subtype was found, particularly in the non-pCR group (5-year OS and DFS, P < 0.001, respectively).
  
  
  CONCLUSIONS
  The non-pCR group showed significantly decreased 5-year OS and DFS rates compared to the pCR group, especially in triple negative and HER2-enriched breast cancer patients. A significant difference in survival rates and molecular subtypes was found in patients who failed to attain pCR.
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hakyoung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Huh
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Doo Ho
authors.initials: DH
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jae Myoung
authors.initials: JM
authors.lastname: Noh
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Young-Hyuck
authors.initials: YH
authors.lastname: Im
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Park
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seok Jin
authors.initials: SJ
authors.lastname: Nam
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jeong Eon
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Yoon
authors.initials: EY
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D055815:Young Adult
keywords: breast cancer; molecular subtypes; neo-adjuvant chemotherapy; radiotherapy