title: Increased sclerostin levels after further ablation of remnant estrogen by aromatase inhibitors.
abstract: BACKGROUND
  Sclerostin is a secreted Wnt inhibitor produced almost exclusively by osteocytes, which inhibits bone formation. Aromatase inhibitors (AIs), which reduce the conversion of steroids to estrogen, are used to treat endocrine-responsive breast cancer. As AIs lower estrogen levels, they increase bone turnover and lower bone mass. We analyzed changes in serum sclerostin levels in Korean women with breast cancer who were treated with an AI.
  
  
  METHODS
  We included postmenopausal women with endocrine-responsive breast cancer (n=90; mean age, 57.7 years) treated with an AI, and compared them to healthy premenopausal women (n=36; mean age, 28.0 years). The subjects were randomly assigned to take either 5 mg alendronate with 0.5 μg calcitriol (n=46), or placebo (n=44) for 6 months.
  
  
  RESULTS
  Postmenopausal women with breast cancer had significantly higher sclerostin levels compared to those in premenopausal women (27.8±13.6 pmol/L vs. 23.1±4.8 pmol/L, P<0.05). Baseline sclerostin levels positively correlated with either lumbar spine or total hip bone mineral density only in postmenopausal women (r=0.218 and r=0.233; P<0.05, respectively). Serum sclerostin levels increased by 39.9%±10.2% 6 months after AI use in postmenopausal women; however, no difference was observed between the alendronate and placebo groups (39.9%±10.2% vs. 55.9%±9.13%, P>0.05).
  
  
  CONCLUSIONS
  Serum sclerostin levels increased with absolute deficiency of residual estrogens in postmenopausal women with endocrine-responsive breast cancer who underwent AI therapy with concurrent bone loss.
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Wonjin
authors.initials: W
authors.lastname: Kim
authors.affiliation: The Graduated School Yonsei University, Seoul, Korea.
authors.forename: Yoonjung
authors.initials: Y
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Kwandong University College of Medicine, Incheon, Korea.
authors.forename: Se Hwa
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sehee
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Bae
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Gyuri
authors.initials: G
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jo Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of General Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byeong Woo
authors.initials: BW
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Kil
authors.initials: SK
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Endocrine Research Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. YUMIE@yuhs.ac.
authors.forename: Yumie
authors.initials: Y
authors.lastname: Rhee
keywords: Aromatase inhibitors; Breast neoplasms; Osteoporosis; Sclerostin
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