title: Age, breast cancer subtype approximation, and local recurrence after breast-conserving therapy.
abstract: OBJECTIVE
  Prior results of breast-conserving therapy (BCT) have shown substantial rates of local recurrence (LR) in young patients with breast cancer (BC).
  
  
  METHODS
  We studied 1,434 consecutive patients with invasive BC who received BCT from December 1997 to July 2006. Ninety-one percent received adjuvant systemic therapy; no patients received trastuzumab. Five BC subtypes were approximated: estrogen receptor (ER) or progesterone receptor (PR) positive, HER2 negative, and grades 1 to 2 (ie, luminal A); ER positive or PR positive, HER2 negative, and grade 3 (ie, luminal B); ER or PR positive, and HER2 positive (ie, luminal HER2); ER negative, PR negative, and HER2 positive (ie, HER2); and ER negative, PR negative, and HER2 negative (ie, triple negative). Actuarial rates of LR were calculated by using the Kaplan-Meier method.
  
  
  RESULTS
  Median follow-up was 85 months. Overall 5-year cumulative incidence of LR was 2.1% (95% CI, 1.4% to 3.0%). The 5-year cumulative incidence of LR was 5.0% (95% CI, 3.0% to 8.3%) for age quartile 23 to 46 years; 2.2% (95% CI, 1.0% to 4.6%) for ages 47 to 54 years; 0.9% (95% CI, 0.3% to 2.6%) for ages 55 to 63 years; and 0.6% (95% CI, 0.1% to 2.2%) for ages 64 to 88 years. The 5-year cumulative incidence of LR was 0.8% (95% CI, 0.4% to 1.8%) for luminal A; 2.3% (95% CI, 0.8% to 5.9%) for luminal B; 1.1% (95% CI, 0.2% 7.4%) for luminal HER2; 10.8% (95% CI, 4.6% to 24.4%) for HER2; and 6.7% (95% CI, 3.6% to 12.2%) for triple negative. On multivariable analysis, increasing age was associated with decreased risk of LR (adjusted hazard ratio, 0.97; 95% CI, 0.94 to 0.99; P = .009).
  
  
  CONCLUSIONS
  In the era of systemic therapy and BC subtyping, age remains an independent prognostic factor after BCT. However, the risk of LR for young women appears acceptably low.
authors: Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA 02215, USA.
authors: Nils D
authors: ND
authors: Arvold
authors: Alphonse G
authors: AG
authors: Taghian
authors: Andrzej
authors: A
authors: Niemierko
authors: Rita F
authors: RF
authors: Abi Raad
authors: Meera
authors: M
authors: Sreedhara
authors: Paul L
authors: PL
authors: Nguyen
authors: Jennifer R
authors: JR
authors: Bellon
authors: Julia S
authors: JS
authors: Wong
authors: Barbara L
authors: BL
authors: Smith
authors: Jay R
authors: JR
authors: Harris
mesh_terms: D000367:Age Factors; D001943:Breast Neoplasms / Q000145:classification* / Q000473:pathology / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000145:classification* / Q000473:pathology; D011379:Prognosis; D018714:Radiotherapy, Adjuvant