title: Breast density change as a predictive surrogate for response to adjuvant endocrine therapy in hormone receptor positive breast cancer.
abstract: BACKGROUND
  Anti-estrogen therapy has been shown to reduce mammographic breast density (MD). We hypothesized that a short-term change in breast density may be a surrogate biomarker predicting response to adjuvant endocrine therapy (ET) in breast cancer.
  
  
  METHODS
  We analyzed data for 1,065 estrogen receptor (ER)-positive breast cancer patients who underwent surgery between 2003 and 2006 and received at least 2 years of ET, including tamoxifen and aromatase inhibitors. MD was measured using Cumulus software 4.0 and expressed as a percentage. MD reduction (MDR) was defined as the absolute difference in MD of mammograms taken preoperatively and 8-20 months after the start of ET.
  
  
  RESULTS
  At a median follow-up of 68.8 months, the overall breast cancer recurrence rate was 7.5% (80/1065). Mean MDR was 5.9% (range, -17.2% to 36.9%). Logistic regression analysis showed that age < 50 years, high preoperative MD, and long interval between start of ET to follow-up mammogram were significantly associated with larger MDR (p < 0.05). In a survival analysis, tumor size, lymph node positivity, high Ki-67 (≥ 10%), and low MDR were independent factors significantly associated with recurrence-free survival (p < 0.05). Compared with the group showing the greatest MDR (≥ 10%), the hazard ratios for MDRs of 5-10%, 0-5%, and < 0% were 1.33, 1.92, and 2.26, respectively.
  
  
  CONCLUSIONS
  MD change during short-term use of adjuvant ET was a significant predictor of long-term recurrence in women with ER-positive breast cancer. Effective treatment strategies are urgently needed in patients with low MDR despite about 1 year of ET.
authors: Jisun
authors: J
authors: Kim
authors: Wonshik
authors: W
authors: Han
authors: Hyeong-Gon
authors: HG
authors: Moon
authors: Soo
authors: S
authors: Ahn
authors: Hee-Chul
authors: HC
authors: Shin
authors: Jee-Man
authors: JM
authors: You
authors: Sae-Won
authors: SW
authors: Han
authors: Seock-Ah
authors: SA
authors: Im
authors: Tae-You
authors: TY
authors: Kim
authors: Hye
authors: H
authors: Koo
authors: Jung
authors: J
authors: Chang
authors: Nariya
authors: N
authors: Cho
authors: Woo
authors: W
authors: Moon
authors: Dong-Young
authors: DY
authors: Noh
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D015415:Biomarkers; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003720:Densitometry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012307:Risk Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D018931:Antineoplastic Agents, Hormonal; D015415:Biomarkers; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone