title: Effects of the expression of leptin and leptin receptor (OBR) on the prognosis of early-stage breast cancers.
abstract: OBJECTIVE
  Obesity-related leptin and leptin receptor (OBR) have a relation to the development of cancer and metastasis and also the low survival rate for breast cancer patients. Leptin has been associated with increased aromatase activity and it displays functional cross-talk with estrogen. This study was designed to determine the relationship between the expression of leptin and OBR in breast cancer tissue and the prognosis of early-stage breast cancer patients, and especially for the tamoxifen-treated patients.
  
  
  METHODS
  Ninety-five patients with early-stage breast cancer and who had undergone surgical treatment at Kyung Hee University Hospital between January 1994 and June 2004 were analyzed. The surgical specimens underwent immunohistochemical analysis for leptin and OBR. The patients' survival and clinical characteristics were obtained from the medical records.
  
  
  RESULTS
  Of the 95 patients, 79 (83%) and 32 (33.7%) showed the expression of leptin and OBR in breast cancer tissue, respectively. The expression of leptin and OBR in breast cancer tissue was not significantly related to the clinicopathological characteristics, including obesity, the expression of hormonal receptor, the HER-2/neu expression, menopause, stage and the nuclear grade. The expression of leptin and OBR was not significantly related to the overall disease-free survival (DFS). For the tamoxifen-treated postmenopausal obese patients, the DFS of the leptin-positive group was higher than that of the leptin-negative group (p=0.017).
  
  
  CONCLUSIONS
  The expression of leptin and OBR in breast cancer tissue may be not a prognostic factor for disease-free survival of breast cancer patients. In the future, further studies are needed to determine whether leptin expression could be a predictive factor for tamoxifen therapy in the postmenopausal obese subgroup among the early breast cancer patients.
authors.affiliation: Division of Hemato-Oncology, Department of Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
authors.forename: Yongnam
authors.initials: Y
authors.lastname: Kim
authors.forename: Si-Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Jae Jin
authors.initials: JJ
authors.lastname: Lee
authors.forename: Jeongho
authors.initials: J
authors.lastname: Seo
authors.forename: Youn-Wha
authors.initials: YW
authors.lastname: Kim
authors.forename: Suck Hwan
authors.initials: SH
authors.lastname: Koh
authors.forename: Hwi-Joong
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Kyung Sam
authors.initials: KS
authors.lastname: Cho